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ANATOMY

PHYSIOLOGY

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RASSWEILER

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UNIVERSITY OF CALIFORNIA.

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THE TEACHERS' MANUAL

PUPILS' TEXT BOOK

Anatomy, Physiology and Hygiene.

INCLUDING THE EFFECTS OF

ALCOHOL AND NARCOTICS UPON
THE HUMAN SYSTEM,

DESIGNED TO ACCOMPANY

THE TEACHERS' ANATOMICAL AID

IJY

PROF. J. K. RASSWEILER, A. M.

PUBLISHED BY

CENTRAL SCHOOL SUPPLY HOUSE,
CHICAGO, ILLINOIS.

BIOLOGY

LIBRARY

G

Entered according to Act of Congress, in the year 1889,

BY CENTRAL SCHOOL SUPPLY HOUSE,
in the office of Ihe Librarian of Congress, at Washington, D. C

PREFACE.

This book is intended to go into the schools of
the country as a companion to the " TEACHERS' ANA-
TOMICAL AID," which is supposed to be before the
class during every exercise or recitation in Physi-
ology, and to which the illustrative references, found
throughout these pages, relate.

To the teacher who gives oral lessons in Physi-
ology, by the use of the Aid, this volume offers
assistance in presenting the truths of the science in
proper order, plain language, and with many illus-
trations gathered within the range of the pupils'
observation and experience. Thus, even inexperi-
enced teachers are furnished with methods and
material to conduct a well-arranged course of daily
drills on a subject of surpassing importance and
interest.

To the teacher who conducts a recitation, with the
use of the Aid, this work offers guidance in point-
ing out, precisely, by its frequent references, those
parts or features on the plates or manikin sections,
which illustrate any topic in hand, as found in the
current text-books on Physiology.

While this book is thus intended to be helpful to
(1)

2 PREFACE.

teachers of all grades of experience, it is, at the
same time, adapted for use as a text-book for ele-
mentary classes. The practical results which may
be obtained from such a use of it, in connection
with the Anatomical Aid, will be found to be more
satisfactory than those which can be attained by any
other method of instruction in the elements of
Physiology.

When used as a text-book with the Aid, the latter
should be made conveniently accessible to the
pupils. This can easily be done in any school-
room. The objection that the pupils will injure the
charts by handling them, is a mischievous notion.
They are entitled to such privileges. If well and
kindly advised, they will handle them properly and
will take pride in carefully preserving them from
injury.

TABLE OF CONTENTS.

THE SKELETON.

PAGE.

Bones— Like the Framework of a House— Number of Bones— Shape— *
Structure— How United— Bound Together by Ligaments— Uses
of the Bones— Division of the Skeleton— Table of the Skeleton—
Bones of the Head— The Skull— The Face— Bones of the Trunk—
The Spinal Column— Vertebrae— The Chest— The Pelvis— Bones of
the Upper Extremities— The Shoulder— The Arm— "Bones of the
Lower Extremities— T\\Q Thigh— Lower Leg and Foot— Health of
the Bones— Outline— Questions 5

THE MUSCULAR- SYSTEM.

The Muscles— Number and Structure of Muscles— Tendons— Use of
the Muscles — Language of the Muscles — Two Kinds of Muscular
Action— How Muscles Act— Antagonists or Counter Muscles-
Some Prominent Muscles and Their Names— Health of the Mus-
cles— Outline — Questions 19

THE NERVOUS SYSTEM.

The Brain - Structure— Protection to the Brain— Divisions of the
Brain — Hemispheres — Work of the Cerebrum — Work of the Cere-
bellum—The Spinal Cord— The Nerves— iNervous Action— Reflex
Nervous Action — Sympathetic Nervous Action — Health of the Ner-
vous System— Outline— Questions 29

THE SPECIAL SENSES.

Nerves of Common Sensation— Nerves of Special Sensation— The
Eye— Protection of the Eye— Tear Apparatus— The White Coat of
the Eyeball— The Black Coat— The Nervous Coat-Thp Humors of
the Eye— 7 he Kar-The Nerve of Hearing— The Outer Kar— The
Middle Ear -The Inner Ear— How We Hear— The Sense of Smell-
How We Perceive Odors— The Sense of Taste— The Tongue— How
We Perceive Taste^- Outline— Questions 41

THE CIRCULATORY SYSTEM.

Organs of the Circulatory System— The Heart— The Arteries— The
Veins— The Capillaries— Blood Change in the Capillaries -The
Course of the Blood— Three Divisions of the Circulation— Inter-
esting Facts— Health of the Circulatory System— Outline— Ques-
tions 54

THE RESPIRATORY SYSTEM.

Structure of the Lungs— Use of the Lungs— Breathing— How We
Breath— Chief Breathing Muscles— Pleura— Health of the Respira-
tory Organs — Exercise — Impurities of the Breath — Ventilation —
The Voice— The Larynx— An Experiment— Speech— Outline-
Questions 62

4: CONTENTS.

THE DIGESTIVE SYSTEM.

Body— Building from Blood— Aid of the Muscular System— Work of
the Teeth -Number of Teeth— Structure of a Tooth— Work of the
_ Salivary Glands— Work of the Pharynx and Oesophagus— Work of
the Stomach— Use of the Gastric Juice— Work of the Pylorus-
Work of the Liver— Work of the Pancreas— Health of the Diges-
tive System -Eating too Fast— Eating too Much— Eating too Fre-
quently-Eating Indigestible Food— Exercise— Outline— Questions. 71

THE ABSORPTIVE SYSTEM.

Absorption— Intestinal Villi— Two classes of Absorbents in theViili—
Veins in the Villi - Portal Circulation— The Second Route— Lac-
teals in the Villi— Chyliferous Vessels and Lymphatic Glands-
Thoracic Duct— What Has Been Done— Assimilation— Recapitula-
tion—The Lymphatic Vessels— Lymph— Origin of Lymph— The
Lymphatics— The Lymphatics a System of Drainage— The Lym-
phatic Glands— The Lacteals, a part of the Lymphatics— Lympha-
tics Om pared with the Blood Vessels— Other Functions of the
Lymphatics -Suggestions to the Teacher— Outline— Questions 87

THE EXCRETORY SYSTEM.

Excretory Organs— Impurities .Thrown Off by the Lungs— Carbon Di-
oxide— Carbon Acid Test— Test of the Breath— Watery Vapor Ex-
haled— The Liver— As an Excretor" Organ— The Kidneys— Work
of the Kidneys— The Kidneys at Work — Difference Between the
Secretions of the Liver and Kidneys 93

MICROSCOPIC LESSON.

Its Purpose— The Microscope as an Aid in Physiology— Microscopic
Structure of the Arteries— Ot the Veins— Of the Capillaries— Of
the Mucus Membrane— Of the Looped Capillaries of the Skin— Of
the Intestinal Villi -Of the Air Cells of the Lungs— Capillaries
of the Parotid Gland, Brain and Cellular Tissue— Of the Elastic
Tissues. Muscular Fiber and Bone Corpuscles — Of Voluntary Mus-
cles—Of the Glands of the Stomach— Of the Nerve Fibers of the
Brain— Of the Hepatic Vein— Of the Kidney Structure- Of Red
Blood Corpuscles— Of Tendinous Fiber— Adipose Tissue— Epithe-
lial Cells— Cells of Epidermis— Pigment from Choroid Coat of
Jiye— Other Views 98

EFFECTS OF ALCOHOL.

Value of a Sound Body— Abuse of the Body— Strong Drink— Alcohol
and What is It! What is Its Origin— How is It Done— Fermenta-
tion—Acetous Fermentation — Beer from Barley— Distillation —
Two Classes of Strong Drink— A Healthy Stomach— Inflamma-
tion -Uloeration— Last Stages of Alcohol Poisoning— Alcohol
and the Liver— The Result— Alcohol and the Kidneys- Effects on
the Brain— The Brain the geat of the Mind— Consequences Alco-
holic Softening of the Brain— Delirium Tremens— Effect on the
Nerves— Different Effects of Intoxicants upon the Heart— Synop-
sis—What It Will not Do 106

TOBACCO AND ITS EFFECTS.

Tobacco is a Poison— Its Effects upon the Young— Cigarette Smoking—
An Experiment— The Respiratory Organs— How Affected -Con-
clusion 119

OF THB

UNIVERSITY

THE SKELETON.

BONES.

Like the The framework of the body is com-
r/a^ouse1* Posed °^ bones and ligaments. It is
called the skeleton. What beams, joists
and rafters are to a house, bones are to the body.
As each timber in the framework of a building is
fitted for its own particular place and purpose, so
each one of the bones of the body has its own place
and is in every way precisely adapted, in shape and
•strength, for a special use.

There are two hundred and eight bones
Number jn ^Q gkeieton. This does not include

oi Bones.

the teeth, for they are really not a
part of the skeleton. Thirty-four of the bones of
the body are single — only one of the same kind.
Besides these, there are eighty-seven pairs, the two
bones of each pair being alike — one on each side of
the body.

The skeleton plate shows that the bones

Shape. ...-„ . _.

are very different in shape. Some are
long, like this (leg bone), for example. Others

(5)

6 ELEMENTARY PHYSIOLOGY.

are nearly round, like these bones of the wrist.
Some are quite flat, like this large, spreading bone
at the shoulder (16), or these broad bones in the
lower part of the main body (3).
structure ^~^6 bones are very hard and strong.
"Hard as a bone" is a familiar compar-
ison. We shall not be surprised at their hardness
aod strength when we shall have learned what im-
portant uses they serve in the body. There are two
kinds of material in the structure of a bone. One
part is called animal matter and the other is called
mineral matter. If the bone were composed of
animal matter alone, it would bear no pressure and
keep no permanent shape. If it were made entirely
of mineral matter it would be too brittle, and conse-
quently would break very easily. So these two kinds
of material 'are united together in such a way as to
secure strength without too great brittleness. In
childhood the bones are not easily broken. This is
because in early life they contain about twice as
much animal matter as mineral matter. What a wise
protection against the "bumps" and "tumbles" of
the little ones. In middle life the two kinds of
material are more nearly equally divided. In old
age, however, the bones are very brittle, because,
then, there is about twice as much mineral matter as
animal matter in their structure.

It is an easy and interesting experiment to sepa-
rate these two kinds of bone material . Throw a flat
bone, or piece of bone, into the fire. After a while

THE SKELETON. 7

you will find a part of it, like a cinder, among the
ashes. This is the mineral part. The fire has
burned out the animal matter. Take the "drum-
stick" bone of a chicken and place it in a bottle con-
taining a mixture made by filling the bottle half full
of water and adding about half as much muriatic
acid — a common drug which you can get for a trifle
at the nearest drug store. This will take out the
mineral matter from the bone and leave the animal
matter. The mineral matter which you took from
the fire was brittle or crumbling. The animal
matter, when taken from the acid, is gluey and can
be wound, like a cord, about the finger. The broad
or flat bones, like those of the head, are not entirely
solid. Between the two outside layers of such a bone
there is a layer of spongy-like material. These
three layers of structure in a flat bone can be clearly
seen hy looking at the edge of such a bone which
has been sawed through.

The long bones are generally hollow and contain
a substance called marrow. At the ends they are
usually thicker and more spongy. This serves to
break the force or shock of heavy stepping or jump-
ing with the lower limbs, or a hard stroke with the
arm. The ends of the long bones are also covered
with a smooth, white substance called cartilage.
This aids in giving the bone an easy motion at the
joint where it is united to another bone.

8 ELEMENTARY PHYSIOLOGY.

The bones are united to each other in
United, different ways. Those which are quite

movable are connected by joints. Some
of these are called hinge-joints because they work
like the hinge of a door. These (arm) bones
which meet at the elbow are hinge-jointed. Eaise
and lower your forearm and notice particularly how
the joint acts. The joints in the fingers and the
knee are also hinge-joints. Another kind is called
the ball and socket joint, where the round end of one
bone moves in a hollow place of another. Here (a)
at the hip is a good example of a ball and socket
joint, where the round head of this large upper bone
of the leg moves in a deep hollow of this lower bone
of the main body. The bones of the head meet each
other with jagged edges forming a seam-like junc-
tion called a suture. One of these is clearly shown
on this skeleton (12). Between the bones of the
back are placed cushions of cartilage. This is a
substance softer than bone and quite elastic, like
rubber. This cushion arrangement between the
bones of the back, is nicely shown on this plate.
(Refer to cartilages between lumbar vertebrae.)

The bones are bound to one another

Bound To- . _

Bother by by ligaments. These are very strong
Ligament*. and hol(j foe bones firmly in position.
Some of these stout bands or ligaments are shown on
this plate. Here (XVI) are the ligaments which
bind together the bones of the hip. These (XXV,
XXVI) are the ligaments of the elbow joint

THE SKELETON. 9

The bones of the body serve several
important purposes. 1. They give the
body its general shape. 2. They sup-
port the softer material of the body within and
around them. 3. They protect delicate and impor-
tant parts against injury from without, as, for exam-
ple, the brain, lungs and heart. 4. They serve as
levers, to be moved by the muscles in the various
movements of the body, as we shall learn more
clearly, somewhat later.

^ the figure of the skeleton

of the we perceive that the bones are grouped

Skeleton. . , - , ,. . . , 1

into four natural divisions, namely: 1.
The bones of the head. 2. Those of the main body,
or trunk. 3. Those of the upper extremities, or
arms. 4. Those of the lower extremities, or legs.

We have now learned about the number, shapes,
material, union, uses and groups of the bones of the
skeleton. We are now ready to study the more
important bones of each group more closely.

10

ELEMENTARY PHYSIOLOGY.

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THE SKELETON. 11

BONES OF THE HEAD.

There are twenty-two bones in the head.
skull, - 0£ these are shaped and united in

such a way as to form a sort of round box which is
called the s/atZZ, or cranium. This is one of the most
important parts of the skeleton, since it contains the
brain, the most delicate organ of the body. The
word organ, in physiology, means any single part of
the body which serves a special purpose. Thus, the
brain, heart, lungs and veins are organs. The skull,
or brain-box, is placed, like a dome, at the top of the
structure of the body. It is wonderfully fitted for
the protection of its tender contents. It is shaped
for strength as well as for beauty.

The front of the skull is formed by the frontal
bone (1), or bone of the forehead. The two parietal
bones (2) form the upper sides, and the two tem-
poral bones (3) form the lower sides of the skull.
At the back of the head (4, back view of skeleton)
is the occipital bone. Two more of the skull bones
form its lower part or base. These we will not
name here ; but you will find them named in the full
table of the bones which has been given.

The remaining fourteen bones of the

The Face.

head give shape to the face. The two
nasal bones (6) form the bridge of the nose, and the
two malar bones (4) the prominence of the cheeks.
The upper jaw is formed of the two upper maxillary
bones (7). The lower jaw bone (8) is called the

12 ELEMENTARY PHYSIOLOGY.

lower maxillary. The teeth are set in sockets of
these maxillary bones.

BONES OF THE TRUNK.

The main body is called the trunk. The upper
part of the trunk is fitted to contain the lungs and the
heart. Its lower part contains .the stomach, liver and
bowels.

The great pillar of the body is the spinal
column!** column. It bears aloft the head — the

crowning part of the whole structure. It
supports the great vital organs of the main body.
It is most wonderfully constructed with reference to
comfort and safety of life. Instead of being com-
posed of but one or a few bones, it is built up of
twenty-six pieces, which, while laid up one above the
other, are separated from each other by very elastic
cushions of cartilage. This does not only make the
back-bone capable of bending forward, backward and
sideways, but it makes the whole pillar springy, so
that the delicate brain which rides at its summit is
not affected by jarring from the heavy movements of
the body.

Twenty-four of the bones of the spinal

column, or back, are called veriebrce
These are firmly bound together by ligaments and
interlocked with each other by their own projecting
parts. An opening runs through each vertebra.
These openings form the spinal canal through which

THE SKELETON. 13

the spinal cord, of which we shall learn hereafter,
passes. The vertebrae are divided into three sets. The
seven upper ones are in the neck. The next twelve
are in the back proper; to these the twelve pairs of
ribs are attached. The five lower vertebrae are in
the region of the loins. They are very stout, as the
figure shows, just as we would expect them to be,
since they support a large part of the weight of the
body.

The upper part of the trunk, which con-

The Chest.

tains the heart and lungs, is called the
chest. The skeleton of the chest is formed behind,
as you see, by the middle division of the spinal col-
umn; on the sides by the ribs (12, 13), and in front
by the sternum (10) or breast-bone. Here, again, we
find a wise provision for the protection of life. The
breast-bone is not near so hard as most of the other
bones. It is consequently more flexible. The ribs
are not directly united to the sternum, but are joined
to it by cartilages. By these means, a heavy blow
on the breast, which otherwise would seriously injure
the organs within, is made comparatively harmless.
The plate of the skeleton shows that the ribs are
not all joined to the breast-bone in front. Seven
pairs (12-13) are so joined. These are called true
ribs. The remaining five pairs (14-15) are called
false ribs.

The bones of the lower part of the trunk

The Pelvis. , ., . . ..

are shaped and joined so as to form a
large bowl-shaped cavity. This is called the pelvis.

14 ELEMENTARY PHYSIOLOGY.

Notice how broad and peculiarly formed these two
(3) bones are. The sacrum (1) bone is wedged
between these two bones at the back.

BONES OF THE UPPER EXTREMITIES.

The In examining the shoulder, we first notice

shoulder, these two collar-bones (8). Their use is
to brace the shoulders properly apart ; so one end
rests against the breast-bone and the other against
the shoulder. Next comes the shoulder-blade. (16).
These are so broad to allow the attachment of some
very strong muscles of the upper part of the body.
The upper arm has one large bone called

Tin* Vrm

the humerus ( 1 ) . The radius ( 2 ) and the
ulna (3) are the bones of the lower arm. There
are eight roundish little bones in each wrist (4), five
longer ones in the middle of each hand (5), three
short bones in each finger (6, 9, 10) and two in each
thumb (7, 8).

BONES OF THE LOWER EXTREMITIES.

Here we meet the largest bone of the

The Thigh. _ . , ,.. Tl . ,, .. . ,,

skeleton (1). It is called the femur.
Observe the round shape of its upper end (a). This
is called the head of the femur. Moving in a hollow
place of this large bone (3) ,it forms the ball and socket
joint of the hip. Do not fail to notice how securely
the lower limbs are bound to the main body by these
numerous strong ligaments.

THE SKELETON.' 15

The lower leg has two bones — the tibia
and Foot!* (a)> and the^ftwZa (b). The knee-joint,
between the thigh bone and the bones of
the lower leg, is protected by a flat bone called the
knee-pan (2). There are seven bones in each heel,
five in the middle part of each foot, three in each of
the larger toes, and two in each great toe.

Notice this peculiarity in the form of the foot. It
is curved or arched from the heel to the front.
Here is another arrangement for springiness, with-
out which, walking would not only become clumsy
but painful.

The bones of a grown person are so much
hardened by the mineral matter which
has increased in their structure, that they
are not easily changed in shape. They are more
easily broken than bent. Neither is the full-grown
joint likely to change in shape and character during
the active years of life. So the general carriage of
the body in adult life, depends on the habits and
circumstances which shaped it in youth. We have
learned that in childhood the bones are quite flexible
and disposed to bend, instead of breaking, under a
strain. For this reason, children who begin to walk
very early become more or less bow-legged. Pupils
who are in the habit of leaning forward on the desk,
in school, will certainly, more or less deform their
bodies. If a boy, in walking, carries his body in a
lazy, stoop-shouldered position, he will go bent and
deformed through life. Avoid leaning the body

16 ELEMENTARY PHYSIOLOGY.

forward in sitting. When lying down, do not
bolster up the head with high pillows. While stand-
ing or walking, hold the head erect, throw the shoul-
ders back, and take in full breaths of air. If these
positions in lying, sitting, standing or walking are
carefully kept in youth, all the curvings and efforts
of the body and limbs which come from ordinary
labor, will not injure them, and the full-grown figure
will be straight, graceful and strong.

OUTLINE.

THE BONES OF THE SKELETON.

framework of the body.

208. Eighty-seven pairs. Thirty-four single.

Shapes: Long, flat, round, irregular.

Composed of animal and mineral matter.

United by joints, sutures and cartilages.

Bound together by ligaments.

Arranged in four groups:

Head, Trunk, Upper and Lower Extremities.

(* Twenty-two in the head.
I Fifty-four in the trunk.

WHERE? «{ Sixty-four in the upper extremities.
I Sixty in the lower extremities.
^ Eight in the ears.

( To give shape to the body.

To support the softer parts of the body within and
WHY? < around them.

To protect important organs.
I To serve as levers to be moved by the muscles.

WHAT? 4

THE SKELETON. 17

SUGGESTIONS TO THE TEACHER.

Be sure that the acid and burning experiments on the com-
position of bones are performed either by yourself or by the
pupils. Get a piece of flat bone sawed to show the layers.
Get a leg joint at the butcher's; remove muscles and tendons, to
show the ligaments; then sever the bones at the joint to show
cartilage. Show a fresh piece of long bone containing marrow.

TEST QUESTIONS.

Of what is the skeleton composed?
To what parts of a house are the bones compared?
How many bones in the skeleton?
Do the teeth belong to the skeleton proper?
How many single bones in the body?
How many are in pairs?
What variety of shapes have the bones?
What two kinds of material in the bones?
Which material makes the bone flexible?
What is the effect of the mineral matter?
How do these materials vary at different ages?
What wise provision in this arrangement?
Why are the ends of the long bones more spongy?
Why are they covered with cartilage?
In what ways are the bones united?
Locate a hinge-joint of the body.
Where is a ball and socket joint found?
What bones are united by sutures?
What bones are united by cartilages?
Ho\v are the bones bound to each other?
Name four uses of the bones.
Into how many groups are the bones divided?
What is the skull?

Point out on the Aid, the frontal bone, — the parietal — tem-
poral— occipital.

How many bones form the face?
What two form the bridge of the nose?
Where are the malar bones?

18 ELEMENTARY PHYSIOLOGY.

The upper maxillary? Lower maxillary?

What is meant by the trunk?

Where is the spinal column?

Why is it built so strong?

How is it made, elastic or springy?

What benefit in this arrangement?

How many vertebrae in the back-bone?

How many of these are in the neck?

How many have ribs attached to them?

How many are in the loins?

What bones make the frame of the chest?

Are the ribs united directly to the sternum?

Is the sternum as hard as other bones?

What benefit in these arrangements?

How is the lower part of the skeleton of the trunk shaped?

What is it called?

What three bones come together at the shoulder?

What two in the forearm?

How many in the wrist?

How many in the middle of the hand?

In each finger?

In each thumb?

Which is the longest bone in the skeleton?

What two bones in the lower leg?

How many heel bones in each foot?

Why is the foot arched instead of flat?

THE MUSCULAR SYSTEM.

MUSCLES.

We have studied the framework or skeleton of the
body. We have seen from the figure of it in the
Anatomical Aid, how it resembles the framework of
a house before it is weather-boarded and shingled.
The plate of the body which is now before us pre-
sents altogether a different view from that which we
have been studying. We notice that it looks more
like the full body, more like a house that is enclosed.
The bones are here quite concealed by another
division of organs — the muscular system. The
word system in Physiology means the whole collec-
tion of parts or organs of the body, which perform
similar work or which work together for some com-
mon purpose. We are already acquainted with the
bony system. We will now study the muscular
system.

The muscles form the lean flesh of the
body. The meat which we eat for food

31 uscles. *

is chiefly muscle. We are all familiar
with the dark red color of beef when it is

(19)

20 ELEMENTARY PHYSIOLOGY.

raw. You have also undoubtedly noticed that the
muscle or lean meat of pork is of a paler red, and
the meat on the breast-bone of a chicken is quite
white; so muscle is not always red; but it is gen-
erally red, and the plate shows us that the muscles
of the human body are of a quite red color.

There are 527 muscles in your body.
Number and Each one of these is made up of many

Structure of J

Muscles. strands or string-like fibers. These

are laid side by sjde in the mniscle,
sometimes making quite a thick bundle. Each fiber
of a muscle bundle is, however, separated from the
rest by a very delicate substance. If you will take
a piece of cooked meat, when it is cold, yo^ can pull
the muscles apart into strands, and these strands
can be separated into many finer fibers or threads of
muscle. "While this is being done, you can observe
the breaking and crackling of the very thin layer of
matter which separates the fibers. The muscles
differ from each other in shape. Some are spread
out much like a fan. Others are -quite circular in
form, like this one (5) around the eye, or this (15)
around the mouth. Some are quite long and of
nearly even thickness. The largest muscle in the
body is this (60), called the tailor muscle. It is
nearly a yard long and does the work of crossing
the legs.

The ends of the muscles are attached to
the bones by means of a hard white sub-
stance or cord, which is called a tendon. These

THE MUSCULAR SYSTEM. 21

tendons are very strong. Besides binding the
muscles very fiiiniy at their ends to the bones, they
are very usefal :n giving a graceful shape to many
parts of the body. For instance, if these (39 and
40) muscles of the forearm, which must have a con-
nection with the fingers, were all continued as mus-
cular bundles, through the wrist, hand and finger-
joints, the hand would have a very clumsy figure.
But these muscles reach out to the finger- joints by
means of their tendons, and these tendons are
neatly bound down, to run snugly along the bones,
by means of ligaments, Kke this (45), so that the
hand is really a very shapely organ. This (63) shows
the tendon of this (62) muscle of the leg, and here
(68) is the tendon of this (66) large muscle of the
thigh.

The muscles have been very appropriately
the called "our servants," furnished us with

Muscles. u the -house ^ which we liye » They are

indeed very faithful servants. It is their work to
move, in many ways, the different parts of the body ;
or, as in walking, to move the body as a whole.
There is no movement of any part of the body which
is not produced by the action of one or more mus-
cles. Every step we take, the slightest motion of a
finger, the movement of the lips in speaking, the
chest in breathing, or the eye in winking - — all
these movements are produced by the muscles.
The rapidity with which these muscles work
is quite astonishing. To be convinced of this,

22 ELEMENTARY PHYSIOLOGY.

we may observe the movements of the fingers
of a skillful pianist or a rapid type-writer. To help
you understand still better how very rapidly the
muscles can act, you may remember that in say-
ing the one word muscle, the mouth, tongue and
voice organs must be pat, in succession, into four
different shapes or positions, all of which is done by
the proper muscles. We must not get the idea that
only the bones are moved by the muscles. Many
other parts of the body are moved by their action.
For instance, the lips in whistling, the eye -lids in
winking, the skin in wrinkling the forehead, or the
heart in its ceaseless beating. When a dog pricks
up his ears, or a horse drives off the flies by shak-
ing his skin, it is done by the action of the muscles.
There is another use which the muscles

Language

of the serve, which is very interesting. It may

be called the language of the muscles,
and it is remarkable how often they speak for us.
A frown on the face is purely the work of the mus-
cles; yet everybody understands its meaning. The
same is true of a smile. You see two men at a dis-
tance standing face to face and near together, with
clenched fist and up-raised arm. You do not hear a
word they say, but the action of their muscles, which
you see, tells you how they feel. You pass near by
a vicious horse, as he lays back his ears, or approach
a dog whose hair on his neck is drawn up stiff and
straight, you hear no sounds, but you understand
the warning. It is the silent but expressive lan-
guage of the muscles.

THE MUSCULAR SYSTEM. 23

_ v Some of the muscles of the body act

Two Kinds »

of Muscular only when they are directed to do so by
the mind or the will, These are called
voluntary muscles. Others act without being con-
trolled by the will. These are called involuntary
muscles. The muscles of the arm, for example, are
voluntary muscles. The muscles which produce the
action of the heart are involuntary. Some muscles
may act either with or without the action of our will.
For instance, the muscles which produce winking
usually " wait for no thinking." But we may will to
wink, and wink whenever we please. On the other
hand, the will usually controls the action of the
motion of the jaws. But sometimes, as in the case
of a chill, these muscles produce chattering of the
teeth rather contrary to the direction of the will.
HOW the Motion is produced by the muscles, by
the contraction of the fibers. A muscle

Act.

shortens more or less according to the
degree of motion which it is to produce. The short-
ening in length is caused by a swelling out of the
muscles sideways. This swelling or bulging of a
muscle can easily be perceived while it is contracted
and pulling or holding the part which it moves.
Grasp your arm between the elbow and shoulder
firmly between your thumb and fingers. Now raise
your forearm toward your shoulder; you feel the
thickening of the muscle which raises your arm.
This (84) is the muscle whose action you so plainly
feel. It is called the biceps muscle of the arm. This

24 ELEMENTARY PHYSIOLOGY.

name means double-beaded, and this muscle is so
called because it lias two upper tendons or starting
places. Here (32) is the one, and here (33) is the
other. The return of the muscle to its usual shape
and length is called its relaxation. The relaxation
of this (34) biceps must take place to permit the
arm to straighten out; but, at the same time, some
other muscle or muscles must contract to move it
into the straight position. A muscle which bends a
part is called a flexor. One which serves to
straighten a part is called an extensor.
. . ._ Most of the muscles of the body are

Antagonists, J

or counter paired off in their work. That is, the
motion of a part produced by a certain
muscle is reversed by the contraction of some other
muscle. Such muscles are called antagonists, or
counter muscles. Here again we refer to the chart
for illustration. To raise the forearm, as we have
seen, this (34) biceps must contract ; but to straighten
it out again requires the action of this muscle (36),
the triceps. So the biceps and triceps are antag-
onists. These muscles (43 and 44) bend the fingers,
while these (51 and 52) straighten or extend them —
another illustration of counter muscles.

The names of the muscles are very

Prominent .

and long and difficult to remember. It

Their Names. wouu be unwise and unreasonable
•to ask you now to learn many of them. But by
studying a few of the more prominent ones you will
learn something about their uses, and also how their

THE MUSCULAR SYSTEM. 25

names are formed. This (1) muscle, which occu-
pies a very prominent place, begins on the occipital
or back bone of the head, and reaches forward to the
skin of the forehead over the frontal bone. Its con-
traction raises the eyebrows and wrinkles the forehead.
It is called the occipito-frontalis. It takes its name
from the parts which it connects. This (15) curious
muscle, when it contracts, puckers the lips. Physi-
ologists call it orbicularis oris. Orbicularis means
circular, and oris means of the mouth. So this
muscle is named from its shape and position. Here
(51) is a muscle which bears the name extensor
indicis, which means the straightener of the index
finger, this being precisely the work which the
muscle performs. This muscle (22) takes its name
from its position under the clavicle or collar-bone.
So it is called the sub-clavian muscle. We see that
some muscles are named after the parts which they
connect; some from their shape and position; some
from the work which they do, and others from their
location. So the many long and difficult names of
the muscles which you find on this plate (to which
the figure seems to be pointing), and which are so
meaningless to you now, are really very expressive
and full of meaning, and may, some day, when you
are more advanced in your studies, become very
interesting to you.

Health ^ie com^or* °^ the body, its grace of

of the form and the prompt activity of all its

es' parts depend very largely on the healthy

26 ELEMENTARY PHYSIOLOGY.

and vigorous condition of all the muscles. To keep
them all in that condition, each one mast be used
without being abused. A muscle which is not used
loses its power of contraction, becomes weak and
flabby, and finally altogether useless. On the other
hand, if a muscle is overworked, it loses its power.
If you were to tie up your arm in a sling, or bind it
down to your side for a long time, you would lose
the use of it entirely. If you should swing your arm
for a long time, the muscles which produce its motion
would cry out in paiuful protest against the abuse
which they suffer ; and were you to disregard their
protest, they would " strike " and refuse, positively,
to do the bidding of your will. The effect of the
vigorous exercise of the muscles without overtaxing
them, is to make them firm and strong; the stout
arm of a blacksmith, and the strong limbs of a foot-
man illustrate this. The difference between the
robust figure and good health of a sturdy country
boy and the slender body and feeble strength of his
young friend in the city, lies mostly in the difference
in amount of their general muscular exercise. But
we must be careful not to mistake a bulky body, or
thickness of the limbs, as a sign of stoutness and
strength of muscle. It is true, indeed, that as the
muscles grow stronger they grow thicker, and conse-
quently increase the size of the limbs and trunk of
the body. But the effect of the fat of the body is
often mistaken for an " abundance of muscle."

THE MUSCULAR SYSTEM.

27

OUTLINE.
THE MUSCLES.

f The lean flesh of the body.
Color, red. Number, 527.
Composed of many fibers.
Shapes : long, fan-shaped, flat and circular.
Bound to the bones by tendons.
WHAT? ^ Voluntary and involuntary.
Have power of contraction.
Swell out when they shorten.
Antagonists produce counter motion.
Flexors bend, extensors straighten.
I Are kept healthy by exercise.

WHERE? -^ Found distributed in all parts of the body.

WHY?

To give motion to all parts of the body by the
contraction and relaxation of their fibers.

SUGGESTIONS TO THE TEACHER.

In these lessons, whether you teach them by oral exercises
or in recitation by the pupils, you can add much interest and
practical instruction by bringing before your class illustrations
of the real working of the parts or organs which are being
studied. This can often be done very conveniently, and will
contribute much to the pupils' knowledge of the functions or
use of the organs (physiology), while the Anatomical Aid gives
them a correct view of the structure (anatomy) of the parts. In
studying the muscles, especially, such real examples of their
work are very easily given. Name and point out on the plate
a certain muscle. Make it serve your will as your pupils look
on. Then let the class, in concert, join you in the perform-
ance. Wrinkle the forehead, close the eyes, pucker the mouth,
swell the cheeks, raise the arm, etc. This will make the
information which is imparted "stick," because it is stored
in the mind among the pleasures of memory.

The "drum-stick" of a chicken — which some pupil may
like to contribute — will, at this stage, furnish a very good object-

28 ELEMENTARY PHYSIOLOGY.

lesson. Show how the muscles are grouped about the upper
part and gradually taper down to the bone. Below the muscle,
lying along the bone, is a tendon. Separate the muscle. If
the "drum-stick" has become cold, after having been cooked,
you may hear the crackling of the delicate little sheaths which
encase the fibers. When you have removed all the muscles,
you have left two representatives of the bony system — the
larger bone, the tibia, and the slender bone by its side, the
fibula, corresponding, in position, to the same bones in the
human body.

TEST QUESTIONS.

What part of the body do the muscles form?

What is the usual color of the muscles?

How many muscles are in the body?

What can you tell of the structure of a muscle?

How do muscles differ in shape?

What is the shape of the muscle which closes the eye?

What and where is the longest muscle of the body?

What is the use of the tendons?

Can you explain how the tendons assist in giving a graceful

shape to the body?
What is the use of the muscles?

What parts, besides the bones, are moved by the muscles?
Can you give an illustration of the language of the muscles?
What is meant by a voluntary muscle?
What is an involuntary muscle?
What is meant by the contraction of a muscle?
What by relaxation?

What is the difference between a flexor and extensor muscle?
What are antagonists or counter muscles?
How is a muscle affected by being unused?
What is the result of too severe exercise?
Is a bulky body always a strong body?
What is likely to make the body bulky?

THE NERVOUS SYSTEM.

So far as we have now studied the body we have its
framework and the muscles which are to give motion
to its various parts. We have learned how the mus-
cles act, and now comes the question : "What causes
them to act as they do? We have learned of the
obedience of the voluntary muscles to the will. But
how does the mind or will direct them token, how
much, and how long to_act? For the purpose of
enabling the mind to control the action of .the mus-
cles, a very interesting system of organs is provided
in the body, namely, the nervous system. This plate
gives us an excellent view of it.

The brain is, in many respects, the most

The Brain. . _ ,. _ r 1

important organ of the body. It occu-
pies the loftiest chamber of the body house. (Raise
the face section and refer to the brain on plate. )
Here the mind — the invisible tenant or occupant of
the body — seems to form its purposes and send out
its orders to its hundreds of servants stationed at as
many points, between top and toe. Here, also, it
receives its messages of intelligence from the body

and from the outside world. These messages may

(29)

30 ELEMENTARY PHYSIOLOGY.

bring it pleasure or pain ; and they largely influence
its decisions, its orders and its temper.

The brain is an exceedingly soft and

Structure. . & J

delicate organ. If it were not enclosed
in a triple sac and nicely fitted into its bony cham-
ber it would fall apart from its own weight. It is
composed of two kinds of substance, one of which is
gray in color and the other white. The outer por-
tion of the brain is composed of the gray matter.
The white matter occupies the inside portion.

The brain is surrounded by three coats
Protection or membranes. The one lying next to

to the Brain. J &

it is a delicate covering containing
vessels which supply the brain with blood. This
membrane takes its name from its purpose of careful
protection ; so it is called the pia mater — which
means a tender mother. It lies very close to the
surface, stretching over the little hills and dipping
down into the little valleys, with which the outside
of the brain is covered. Next to the pia mater lies
a membrane so delicate that it was named after a
spider's web — arachnoid. This membrane performs
its work of protection by collecting from the blood a
watery fluid to moisten the surface of the brain and
prevent any possible friction. The outer coat is quite
tough and substantial: so it is called the dura mater,
or hard mother. It lies close to the inside surface
of the skull bones. Now wo can see how the brain
is protected, for instance, against a blow on the head.
The effectof such a blow would be diminished, first, by

THE NERVOUS SYSTEM. 31

the hair, then by the skin and muscles overlying the
skull, then by the bone, next by the hard coat, then
by the water coat, and finally by the soft coat — mak-
ing no less than a half-dozen successive defenses
against harm to the castle of the mind.

The brain is divided into two parts, one

°^ whicl1 is mucb larger tnan the other.

These parts are shown here, in this
section which represents the head as divided from
top to bottom, close behind the ears. We will now
refer to the manikin of the head, where we will get
a very clear view of the size and position of these
brain parts. (Fourth section of the head.) This
(74) large upper brain is called the cerebrum. It
fills the whole front and upper part of the brain-box.
The small brain (75) is called the cerebellum.
Notice that it lies behind and below the large divi-
sion of the brain. When this small brain is cut
through, its inner structure has this tree-like appear-
ance (shown on plate), called the arbor vitce.

Both the cerebrum and cerebellum

Hemisphere*. «••••*•, n i AT

are divided into two parts, called the
right and left hemispheres. The lower parts of the
two hemispheres are united by several small mys-
terious-looking organs, whose particular use has
been a puzzle even to many wise heads, but which
certainly have some special part to perform in the
wonderful control of the-mind over the body. The
last section of the head (turn to it), which repre-
sents it as cut through from front to back, in the

32 ELEMENTARY PHYSIOLOGY.

middle, shows us the right hemisphere of both the
larger and the smaller brain. The red vessels, in the
figure, are blood-vessels which bring large quantities
of the purest blood in the body to the brain, for a
purpose of which we shall learn hereafter.

From many observations and experi-
ments which have been made by
physiologists, it has been learned
that the large brain is the thinking organ of the
mind. It is here that impressions received from
the outside world are translated into thought and
feeling. Here the purposes of the will are formed,
and from here all orders for the action of the volun-
tary muscles are issued.

The work of the small brain seems to

Work of the , . . ,

cerebellum "e to regulate the muscuJar movements
which are directed to be made by the
large brain. It has been discovered that when the
cerebellum is injured, a person can not balance
the body, as is required even in standing and much
more in walking. A bird whose small brain is
seriously injured or removed, can move its wings
and its legs, but it can neither fly nor walk.

The nervous matter of the brain is con-
Cord. P" * tinned down through the back, passing

through openings in the bones of the
spinal column. This is called the spinal cord. Here
(131, last section of the head) is where the spinal
cord begins. This (124) upper part of the cord
(medulla oblongata) is a very important part of the

THE NERVOUS SYSTEM. 33

nervous system, for the reason that it seems to have
control of some of the most vital operations of the
body. When it is injured, .the breathing muscles
fail to act, which, of course, means instant death.
Here (150) we see the spinal cord continued down-
ward. Now we will turn again to the nervous plate of
the Aid, where the whole of this great nervous
cord is shown with its numerous branches of nerves.

The nerves are composed of the same
TheXerves. ji i_ • mi -i

substance as the brain. Iney are sil-
very threads which branch out from the brain and
spinal cord and are distributed to all parts of the
body. Twelve pairs pass out through openings of
the cranium. These are called cranial nerves.
Thirty-one pairs pass out from the spinal cord
through openings of the back-bone, as shown on the
plate. These are called spinal nerves. The cranial
nerves go to the eye, ear, nose, tongue and other
important organs. The spinal nerves go to the
arms, trunk and legs.

Besides the nerves which branch out from the
brain and spinal cord, there is, on each side of the
back-bone, a chain of nerve centers — little bits of
brains, as it were — running down through the body.
From these small nerve knots, delicate nerves run out,
some to the heart, lungs and stomach, and others to
the blood-vessels and to the cranial and spinal
nerves. So all the important organs of the body are,
in this way, connected with each other and with the
brain. This figure (The Sympathetic System) shows,

34 ELEMENTARY PHYSIOLOGY.

beautifully, this wonderful nervous connection. The
interesting object of this arrangement — which is
called the sympathetic nervous system — we shall
soon learn.

There are three kinds of nervous action.
Action!** We will first consider the relation between

mind, brain and nerve. The nervous
system is very much like a telegraph system. The
mind has been called the operator, the brain and
spinal cord the sending or receiving offices or
instruments, and the nerves the wires or lines
running to all parts of the body. The comparison
is very apt, indeed. One set of nerves runs from
the brain or spinal cord to the muscles, so that every
muscular fiber is in direct communication with head-
quarters. Now, wherever a muscle is to act, every
fiber of it, in some mysterious way, gets a message
over its nerve line, from the nervous capital,
directing it precisely how much to contract or relax.
For example, you make up your mind to close your
eyes. The order is sent out over the nerve lines
which go to the fibers of the circular muscle which
we have found to lie around the eye, and promptly
the eyelids close. The nerves which carry messages
to the muscles are called nerves of motion. Another
set of nerves are called nerves of feeling. They
carry impressions from the body to the brain. These
nerves are distributed so thickly near the surface of
the body, in the skin, that it would be almost impos-
sible to find a point on the body where the prick of

THE NERVOUS SYSTEM. 35

a pin would not be felt. If you touch your body on
its skin surface anywhere, even with the fine point
of a needle, you are sure to disturb one or more of
the nerves of feeling. Quicker than thought they
report the impression, according to the degree of its
severity, to the brain, which, if the situation at the
surface demands it, will promptly return an order,
over the nerves of motion, to the muscles of the
endangered part, to do their best to get it out of the
way of harm. For instance, a mosquito may alight
on your forehead so lightly as to make no
impression on your nerves of feeling, and, con-
sequently, you are not aware of it. But now he
punctures the skin and touches a nerve with his
wonderful little stiletto. The news of his attack has
been received by the brain, and an order sent back
for defense and protection. Quicker than thought
your hand has come up and routed or crushed the
little assassin.

But the impressions which the nerves df feeling
carry to the brain and mind are not all alarming or
painful. Many of them are impressions of comfort
or pleasure. A gentle breeze fans your body on a
hot summer day. Hundreds of nerves are telling
it to the mind, which enjoys it as a pleasure. Light
impresses the nerve of sight, and beautiful views
of form and color are spread before the mind.
Sound excites the nerve of hearing and the charms
of music are enjoyed. Invisible particles from a
rose come in contact with the nerve of smell and we
are delighted with the fragrance of the flower.

36 ELEMENTARY PHYSIOLOGY.

If all the muscles were voluntary muscles,
Nervous that is, if no movement of the organs of
on* the body could be made without a special
order from the mind, the continuance and enjoyment
of life would be impossible. Every breath, every
heart- beat, and many other operations of organs
which can scarcely be dispensed with for even a few
moments, would need to be constantly thought of
and directed. Fortunately, the mind, and even the
brain, is relieved from the ordinary control of the
operations of organs upon whose regular and con-
stant action cur life depends. So the heart goes on
beating, the lungs continue breathing and the stom-
ach keeps on working, while the mind rests and the
brain sleeps. Let us see how this is done.

The spinal cord may be regarded as a continua-
tion of the brain. It is composed of the same two
kinds of matter — white and gray. We may also look
upon the spinal cord as a deputy brain. A deputy
is appointed as a substitute for another, and empow-
ered to act for him. An officer may have more duties
to perform than he can personally attend to. So an
assistant is given him, who is entrusted with certain
lines of work for which he is held responsible. When
serious questions or difficulties arise in the assist-
ant's department of work, he appeals for special
advice to the chief officer. So in the body, while the
brain executes the orders of the mind, and controls
the voluntary operations and movements of the body,
the spinal cord is entrusted with the control of the

THE NERVOUS SYSTEM. 37

involuntary muscles which perform the work of the
heart, lungs, stomach and other vital organs, except
in cases of emergency. For example, when food
comes into the stomach, certain movements of the
walls of that organ are necessary. So the food makes
an impression on the nerves which report its pres-
ence, not to the brain or to the mind, as a sensation,
but to the origin center of those nerves, in the spinal
cord. Here the cord exercises its authority and
returns (reflects) an order over motor nerves to the
muscles of the stomach to perform the needed
service.

In the same way, the presence of impure air or
the absence of air in the lungs causes impressions
which are carried to the cord, which returns orders
for the action of the breathing-out or breathing-in
muscles, as the case may be. All these performances
go on steadily, whether we are awake or asleep.
But when an emergency arises, as, for instance, if
the muscles of the chest are strongly resisted in their
efforts to expand it, by outside compression, the
news of the trouble is carried beyond the nerve cen-
ters of the cord up to the brain, where the mind
quickly grasps the situation and promptly issues
orders for the best possible measures of relief. A
familiar illustration of reflex action is found in the
flapping of a fowl whose head has been cut off. Its
muscles which produce its violent motions are not in
connection with the brain, and can not be controlled
by it. Each fall to the ground produces an impres-

38 ELEMENTARY PHYSIOLOGY.

sion which starts from the cord a message for the
repetition of these muscular movements. Even
when it seems to have settled down quietly, if you
touch its body the movements will be renewed.

s m athetic ^e ^ave seen ^ow the sympathetic
nerves connect important organs with

each other and each with the brain. So
if one organ suffers, the others suffer more or less
with it. When the stomach is distressed, the head
aches. When the heart's action is excited, the
stomach is affected. When the brain is impressed
with the mind's sense of shame or modesty, the little
blood-vessels in the skin of the cheeks swell out and
are more than usually filled with blood, and we call
this delicate expression of their sympathy, blushing.
Health of ^e wou^ naturally suppose that organs
the Nervous so delicately constructed, and yet so

prominent in the operations of the body
as those of the nervous system, would need the most
proper care to prevent their derangement or injury.
And so it is. The brain needs especial care. It
needs rest at proper intervals ; not only from severe
application, but the complete rest of sleep. An
overworked brain is a diseased brain. On the other
hand, the brain must have a proper amount of exer-
cise to keep it in vigor. Besides healthy and varied
exercise, the brain needs pure blood regularly and in
proper quantities. Too much or too little blood will
paralyze it. Hence its dependence on the proper
action of the blood-circulating system. Impure

THE NERVOUS SYSTEM.

39

blood will weaken its action. Hence its dependence
on the blood-purify ing system.

Severe excitement of the mind or long continued
anxiety cripple the work of the brain, and finally
result in insanity. A cheerful state of the rnind is
favorable to healthy nerves and long life. Conse-
quently, all proper enjoyments, as the delights of
music, pleasant changes of scenery, varied means of
recreation and social pleasures, are like tonics to the
nervous system first, and through it to the whole body.

There is no system of the body that is more
severely outraged by the habit of drink and the use
of narcotics than the nervous system. But this sub-
ject is so very important that it will be fully explained
in a special chapter, after we are still better
acquainted with the structure of the body.

OUTLINE.
THE NERVOUS SYSTEM.

Consists of brain, spinal cord and nerves.
Very soft and delicate in structure.
Composed of white and gray matter.
The large brain called the cerebrum.
The smaller brain the cerebellum.
Right and left halves of brain — called hemispheres.
Nerves of two kinds, nerves of sensation or im-
pression and nerves of motion.

f Brain enclosed in cranium.
Spinal cord extends from base of brain through

the spinal canal of back-bone.

WHERE. ^ Nerves branch out from the brain, spinal cord and
the sympathetic nerve knots, and are distributed
to all parts of the body.

WHAT?

40 ELEMENTARY PHYSIOLOGY.

To serve the mind in directing the voluntary

movements of the body.
To control, by reflex action, the involuntary mus-

WHY? •{ cles*

To bring to the mind, from the body and from the

outside world, impressions producing the sensa-
tions or feeling of touch, taste, light, sound,
smell, pain or pleasure.

QUESTIONS.

What are the organs of the nervous system?

What position in the body does the brain occupy?

Whose special instrument does the brain seem to be?

What can you say of the brain's structure?

What difference in the color of its substance?

Describe how the brain is protected.

What is the cerebrum?

What is the cerebellum?

What is the arbor vitse?

What is meant by the hemispheres of the brain?

What can you tell of the work of the cerebrum?

What seems to be the use of the cerebellum?

Where is the spinal cord ?

What is its upper part called?

What makes this part so very important?

What are the nerves?

From where do they start?

Where do they go?

How many pairs pass out from the skull?

What are these nerves called?

How many pairs branch off from the spinal cord?

What are these called?

Where do the cranial nerves chiefly go?

To what part are the spinal nerves chiefly sent?

What can you tell of the sympathetic nerves?

To what have we compared the nervous system?

Tell what you can of the comparison.

Do all the nerves perform the same kind of work?

Explain what is meant by the nerves of motion.

THE SPECIAL SENSES. 41

What is meant by the nerves of feeling?

Does the mind attend to all the movements of the body?

If not, will you explain your answer?

What kind of muscles are controlled by the nervous system

independently of the mind?
What is such nervous action called?
Can you give an example of reflex action?
What is sympathetic nervous action?
Can you give an example of it?
Why does the nervous system need special care?
What kind of exercise is needed by the brain?
By what habits are these organs especially injured?

THE SPECIAL SENSES.

All the sensory nerves except four,
Werves of „ ..

common sen- are nerves of common sensation.

They are distributed everywhere
throughout the body. • They need no special organs
to enable them to receive impressions. Near the
surface of the body or in the skin, they end in little
folds or loops called papillce. All the nerves of the
sense of touch are nerves of common sensation.

There are four nerves of special sensa-

Xerves of

Special Sen- tion. These are the nerves of sight,
hearing, smell and taste. Each of these
nerves has a special organ without which no impres-
sion can be received to be carried to the brain.
These organs are very delicate and wonderful struc-
tures. They are really special instruments of the
nervous system.

42 ELEMENTARY PHYSIOLOGY.

THE EYE.
(Third Section of Head Manikin.)

This (46) is one of the nerves of special sensa-
tion— the optic nerve, or nerve of sight. It connects
with and terminates in the eye. This nerve is
impressible only by light. Without the eye, the light
would not impress it. The eye is an instrument to
gather the light which is reflected to it from objects
and to bring it to bear on the optic nerve in such a
way that an impression is made and carried to the
brain, where the mind receives the impression as a
picture of the objects from which the light came.
How all this is done is very mysterious. But the
organs which are concerned in the process can be
easily examined and studied.

Let us notice, first, that the eye is
the Eyl!0n °f l°dged in a deep socket of the bones

of the head. Besides this feature of
protection, there is placed behind and around the
eye, quite a layer of fat, so that, even if the eye is
struck, the force of the stroke is very much lessened
by this fatty cushion. In front, it is guarded by the
eyelids, eyebrows and eyelashes. The eyelids serve
as a curtain. The eyebrows prevent the perspiration
from running down from the forehead upon the lids.
The eyelashes prevent dust from entering between
the eyelids.

(Manikin of the Eye.)

Turning aside this outer section which

ratus.APP*~ represents the natural open eye, we see

a gland lying in the outer corner above

THE SPECIAL SENSES. 43

the eye. This is called the lachrymal or tear gland.
It secretes from the blood a watery fluid which it
pours out upon the eyeball. By the act of winking
the eyeball is entirely bathed by this fluid, which
after it has flowed over the eye, collects in a little
lake at the inner angle, from whence it is drained by
two little channels (2) into the tear duct (1) which
communicates with the nose. Shedding tears is
simply an overflow of this eye-bathing fluid, when
it is secreted in unusual quantity. At such times
the little channels cannot carry it away sufficiently
rapid; so it flows over upon the cheeks. This unu-
sual activity of the tear gland may be produced by
certain states of the mind, as sorrow or great joy;
or by certain diseased conditions of the parts about
the eye, as an inflammation or a severe cold.

The eyeball has three coats. The outer

The wVhite

Coat of the coat, or white of the eye, is called the
Eyeball. sclerotic. It is a strong, tough mem-

brane which forms quite a substantial case into
which the cornea is set in front, like the glass or
crystal of a watch. The sclerotic coat is not sensi-
tive ; that is, it has no nerves of feeling. But it is
covered, in front, with a very delicate membrane
which contains very fine blood-vessels and nerves.
When these little blood-vessels become swollen with
an unusual amount of blood, the eye is said to be
"bloodshot;" and when a cinder or dust grain
lodges on the eye and makes an impression on the
delicate nerves of this fine protecting veil, the sen-

44 ELEMENTARY PHYSIOLOGY.

sation is very painful. No light passes through the
sclerotic coat; but the cornea is very transparent.

Next to the tough outside white coat
The Black Hes ^ choraid. This is a soft black

t^oat.

membrane. It prevents the reflection

of strong light from the inner surf ace of the eyeball,
and this serves an important part in making the sight
sharp and clear. The front part of the choroid coat
is arranged like a circular curtain. This is called
the iris. This is what gives the eye its so-called
color. The difference between a black eye and a
blue eye is, that the cells of the iris of the one have
a black coloring matter in them, while the cells of
the iris of the other contain blue coloring matter.
In the center of the iris is a circular opening called
the pupil which you can see by looking directly into
the eye of another person who stands close before you.
Through this little circular window, surrounded by
the curtains of the iris, the light must pass on its
way to the back inner part of the eyeball. The
amount of light which passes through the pupil is
regulated by an interesting action of the iris. When
the light is strong, the little muscles which are
threaded through the curtain produce the effect of
making the pupil smaller so as to pass less light.
When we go from a light place into a dark, these
same muscles bring about an opposite effect, that is,
the pupil is made larger so as to admit more rays.
This adjustment of the curtain of the eye is not in-
stantly done. It requires some time. This you can

OF T1

TJNIVEB

THE SPECIAL SENSES.

easily observe. For, in going from the dark into a
very light room you can not see well until the change
in the size of the pupil-window of your eye has been
made. So, also, when going from a bright room into
a dark place, at first it seems to be " pitch dark ;"
but, by and by, when your eye is adjusted to the
change, you may be surprised to find that it is not
so dark after all.

The third or inner coat of the eye is
the retina. This lies only over the back
part of the inner »eyeball. It is really
the end of the optic nerve, or nerve of sight, spread
out to receive the impression of the light in the eye.
By turning to the last section of this eye-manikin,
we find this clearly represented. Here is a small
part of the white coat of the back part of the eye-
ball. It shows the opening (23) where the optic
nerve enters through this coat. Turning down the
section which lies just before this, we see the open-
ing (21) for the nerve through (22) the choroid coat.
Turning forward another section we come to the retina
(15) into which the nerve is expanded and over
which the blood-vessels (19, 20) which enter the
eyeball with the nerve, are distributed. The retina
is an exceedingly delicate nervous screen on which
the action of the different parts of the eye makes a
picture of the object we look at. How this picture
is carried by the nerve to the brain and there grasped
or perceived by the mind we do not understand.

46 ELEMENTARY PHYSIOLOGY.

(Sense of Sight.)

Between the cornea and the iris, in the

front Part of the eye» is a watery fluid

called the aqueous humor (18). Back
of the iris lies the crystalline lens (23). This is a
beautiful gem-like little body — as clear as a crystal.
Back of the lens, and between it and the retina, the
eyeball is filled with another clear jelly-like sub-
stance called the vitreous humor (25). The effect
of these three humors which are contained in the
eye, and especially the effect of the lens, is to produce
the image of things on the retina, as has already
been mentioned.

(Third Section of Eye Manikin.)

These muscles, which are shown to be attached to
the outer sclerotic coat, produce some of the prin-
cipal movements of the eye — upward, downward, in-
ward and outward. By the way, we also mention
that the action of the muscles of the iris in regulat-
ing the size of the pupil, is an interesting example of
what we have already learned to name reflex nervous
action.

THE EAR.

The nerve of special sensation which
The iferve goes from the brain to the ear is called

of Hearing.

the auditory nerve. As the nerve of
sight is sensitive only to light, this is sensitive only,
to sound. The ear is an instrument to collect sounds
and bring them to bear on the auditory nerve in

THE SPECIAL SENSES. 47

such a way that an impression is made and carried
to the brain to be recognized by the mind.

The ear is divided into the outer, middle
Outer Ear. and inner ear. Tne outer ear has a

more or less cartilaginous frame. This
allows motion, and, at the same time, keeps it in
shape and position. It has also a few small muscles.
But in the human ear these are nearly altogether
useless, since men do not move or flop their ears.
In animals which move their ears in various ways,
these muscles are quite well developed.

(Sense of Hearing.)

From the outer ear (1) a tube, a little
Ear Middle over an inch long, called the auditory

canal (2), leads in to the middle ear,
where it is closed by a membrane called the mem-
brana tympani, which means the membrane of the
tympanum or drum (3). The middle ear is often
called the "ear-drum," and the membrane just men-
tioned may be called the "drum-head," for it does,
indeed, act very much like the head of a drum.
Between this membrane of the drum and its inner,
opposite side or end, there is stretched a very curious
little suspension bridge of four small bones. The
first of these is attached to the drum-head, and from
its shape like a hammer is celled the malleus (4).
The next is called the incus, because it is shaped
like an anvil (7). The third is a very small pebble
of a bone called the orbicular or round bone (10). It

48 ELEMENTARY PHYSIOLOGY.

is followed by the stapes or stirrup bone (12), the
last span in the little bridge. This rests against a
small window-like membrane which is stretched over
an opening in the inner side of the drum. At the
bottom of the ear-drum or middle ear is an opening
into a tube which leads from the ear to the throat
This is called the Eustachian tube. Its object is to
supply the ear-drum with air, for without air inside
to balance the pressure of the air on the outside
of the drum-head, the action of the latter would be
very imperfect and our hearing, in consequence, very
dull. We frequently experience the truth of this
statement; for whenever the Eustachian tube be-
comes clogged, as in the case of a very bad cold,
our hearing is very much impaired,

The inner ear is carefully hidden in a

Ear InnCr h°U°w Place in tne s°li<i bone- In that
part of it which lies next to the mid-
dle ear, is a little hall-way, or vestibule, about as
large as a grain of wheat. This leads, on one side,
into the arched or semi-circular hall-ways which are
called the semi-circular canals (13, 14, 15). On
the other side the vestibule opens into the cochlea
(16, 17), which is shaped like a snail shell or a tiny
winding stair. Here the auditory nerve, or nerve
of hearing, takes up the impression of a sound and
transmits it to the brain.

All sounds are produced by the vibra-

Hear. tions of bodies. To make this plainer,

when a bell is struck its particles are

THE SPECIAL SENSES. 49

thrown into a violent trembling. By these trem-
blings or vibrations of the material of the bell the
air is thrown into a wave-like motion all around it.
When these trembling air waves reach the ear, the
sensation of sound is produced and we say we hear
the bell. When a person speaks to us the voice
chords in his throat are set into rapid vibration.
These vibrations produce waves of sound in the air;
the air carries these waves to the ear, where, passing
in through the auditory canal they tremblingly beat
upon the drum-head; this carries the sounds to the
bridge of little bones. Having passed over these,
it enters the vestibule, then vibrates into the semi-
circular canals and rebounds into the cochlea, where,
as already stated, it is taken up by the nerve and
carried to the brain where the mind interprets it as
the voice and the language of the speaker.

THE SENSE OF SMELL.

The organ of smell is the nose and its cavities.
The nerve of smell is called the olfactory nerve.
This nerve is spread out in many branches over the
delicate mucous membrane which lines the inside of
the nose. To make the surface on which the nerve
of smell is distributed as large as possible, there is
set into the nostrils, against the outer walls, a pair
of scroll-like bones. These are the turbinatcd bones
of the face. Over their winding surfaces, covered
with the mucous lining, the nerve of smell is spread.
The two small nasal bones unite the nose to the

50 ELEMENTARY PHYSIOLOGY.

skull and keep it in shape. The lower part of the
nose is shaped by a frame of cartilage, the advan-
tage of which over a nose-frame of solid bone you
can readily see.

Things which have an odor, or smell,

MM.O^W \W O

Perceive give out little particles of matter, alto-
gether invisible. As these float in the
air, they are drawn into the breathing passages of
the nose and mouth at every breath. Of course
those which pass with the air into the mouth can
make no impression of smell, for there are no nerves
there which are affected by odors. But those which
pass into the nostrils strike upon the olfactory nerve
branches which, as we have seen, have their special
location there. The mind, receiving these impres-
sions, recognizes the odor, which may be feeble or
strong, agreeable or very unpleasant.

The sense of smell affords us protection in two
important ways. Its organ, the nose, is set at the
very gates of entrance of the air we breathe and the
food we eat. So when the air is filled with putrid
or offensive invisible matter, which, of course, would
make it unfit to breathe,, we are cautioned by the
sense of smell, and instinctively turn away and seek
a purer air to breathe. Likewise, we are often
warned, just in time, against putting into the mouth,
as food, substances whose odor betrays their unfit-
ness to be eaten. Fortunately it is so provided in
nature that poisonous and other harmful substances

THE SPECIAL SESNES. 51

have generally a strong and peculiar smell, although
this is by no means always the case.

THE SENSE OF TASTE.

The special nerves of taste have their
The Tongue, loop-like endings chiefly in the tongue,

which is, consequently, usually spoken
of as the organ of taste. But these papillae, or end
expansions of the nerve of taste are also distributed
over the walls of the back part of the mouth. On
account of the numerous little folds of nerve endings
on the tongue, this organ has quite a velvety appear-
ance. Besides serving as the chief organ of the
sense of taste, the tongue also aids in the chewing
of the food and in producing the sounds of speech.

When substances which have a taste come
HOW We . .

Perceive in contact with the papillae or nerve loops

Taste. Q£ ^e tongue, the impression is at once
carried to the brain and mind. In order that
such an impression can be made the substance
to be tasted must be in a dissolved state.
No dry or solid substance can be tasted. So
-the mouth is" kept moist, and, as we shall learn
later, during the process of eating, a large quantity
of saliva is thrown into the mouth. This dis-
solves at least a portion of the food or substance
which is in the mouth, so that its taste is well per-
ceived. When the mouth is dry from disease, or
from great thirst, food has but little taste and is
very unpalatable. So when the nerves of the tongue

52

ELEMENTARY PHYSIOLOGY.

are covered with a strange coat, as iu disease, our
food does not taste natural.

WHAT

WHEBE?

WHY?

OUTLINE.
ORGANS OF THE SPECIAL SENSES.

T Eye— the organ of sight.

J Ear — the organ of hearing.

] Nose— the organ of smell.

i_ Tongue — the organ of taste.

f Eye — under arch of frontal bone.

J Ear — in hollow of temporal bone.

I Nose — at entrance of air and food passages.

^ Tongue — lies on the floor of the mouth.

f Eye — to collect rays of light from objects and pro-
duce a picture or image of such objects on the
expansion of the nerve of sight.
Ear — to collect sound waves and convey them to

the nerve of hearing.
Nose — to bring odorous matter in contact with the

?aerve of smell.

Tongue— to bring substances having taste in con-
tact with the nerve of taste.

QUESTIONS.

Where are the nerves of common sensation distributed ?

How many nerves of special sensation are there ?

Can these nerves receive impressions directly ?

What is the special instrument of the nerve of sight"?

What is the proper name of the nerve of sight ?

By what only is it impressible ?

What is the use of the eye ?

How is the eye protected by its position ?

What other means of protection are furnished it ?

What is the use of the lachrymal or tear gland ?

Where is this gland situated ?

After bathing the eye, how is that fluid drained away ?

What is meant by "shedding tears" ?

What conditions of mind and body may cause this

THE SPECIAL SENSES. 53

How many coats has the eyeball ?

What is the nature of the outer coafc ?

What is the cornea ?

Is the white coat of the eye sensitive ?

How do you account for the pain felt when a cinder lodges

on the eye ?

What is meant by the eye being " bloodshot " ?
Does light enter the eye through the white coat ?
Through what does it enter ?
What is the color of the middle or choroid coat ?
What purpose does it serve in the eyeball ?
Where and what is the iris ?
What gives the eye its color ?
What is the pupil ?

How is the pupil regulated to admit more or less light ?
Where and what is the retina ?

What is formed by the eye on the screen of the retina ?
What humor lies between the cornea and iris ?
Where and what is the crystalline lens ?
What humor occupies the back part of the eye ?
Which of these parts is most effective in collecting the light

on the retina ?

What is the nerve of hearing called ?
By what only is it impressible ?
What is the work of the ear ?
Into what parts is the ear divided ?
What tube leads from the outer ear to the " drum " ?
Describe the ear drum.
What is the use of the Eustachian tube ?
What are the parts of the inner ear ?
By what are all sounds produced ?

Describe the course of sound-waves from a sounding body
through the ear to the nerve of hearing.

What is the organ ot the sense of smell ?

What is the name of the nerve of smell ?

To what is this nerve sensitive ?

Against what does the nerve of smell afford us protection.

54 ELEMENTARY PHYSIOLOGY.

Where are the extremities of the nerve of taste located ?

What gives the tongue its velvety appearance ?

Why are dry or solid substances tasteless ?

What provision is made to make food more perceptible to

the taste ?
Why does food have no taste to us when we are sick ?

THE CIRCULATORY SYSTEM.

Besides the material which the body needs for its
growth, during twenty years or more, it is constantly
exposed to wear and tear, and, consequently, it must
be supplied continually with material for repair. It
is impossible altogether to avoid the wearing out of
parts of the body. Some of the muscles, like those
of the heart, for example, are on constant duty.
Every contraction of a muscle destroys a part of its
fiber. The nervous system is also constantly suffer-
ing wear. The slightest effort of body or mind pro-
duces damage which must be made good to maintain
our strength. The simplest thought which occupies
the mind lays a tax on the structure of the brain.
Either a wink or a whisper destroys muscular fibers.
If even these gentle movements are wearng, how
great must be the destruction throughout the body?
by labor which exercises vigorously the brain and
many muscles.

So a system of organs is provided in the body,
whose work it is to carry to all parts a supply of

THE CIRCULATORY SYSTEM. 55

material as may be needed for building or repairing.
This is the circulatory system. The blood — a bright
red fluid with which we are all familiar — floats the
building material through the channels and reser-
voirs of the circulatory system. As the building of
a house requires many kinds of material, such as
wood, stone, iron, glass, lime, sand and putty, so the
structure of the body calls for materials suitable for
bone, muscle, nerve, hair, nails, and so on. All this
variety of material is carried by the blood in its
ceaseless rounds through the body.

of the organs and vessels of this system

circulatory are the heart, the arteries, the veins,
and the capillaries. The plate before
us shows the heart in its position, and gives us a very
good idea of the manner in which the arteries and
veins run to and from every part of the body. The
figures of the right arm and right leg are so drawn
by the artist as to show us chiefly the veins of these
limbs, while the figures of the left arm and left leg
show chiefly the arteries.

The heart lies near the center of the

• lit* Heart.

chest, a little to the left of the middle
line. A man's heart is about as large as his fist. It
is a very strong muscular pump or engine and does an
enormous amount of very important work, as we shall
soon see. It has four chambers — two on each side.
The upper chamber of the right side of the heart is
called the right auricle (U) ; below this (W) is the

56 ELEMENTARY PHYSIOLOGY.

right ventricle. The left auricle (V) forms the
upper chamber, and the left ventricle (X) the lower
chamber of the left side of the heart. The upper
and lower chambers — that is, the auricles and ventri-
cles— are separated by valves, whose important use
we will learn when we trace the course of the blood
through the heart.

The arteries are the vessels which

The Arteries. ,, , -, n . .. /.

carry the blood in its course from
the heart. All the arteries which distribute bright
or pure blood from the heart for the nourishment of
the body, are represented by red vessels on the plate.
This large artery — the pulmonary artery (16) —
carries dark or impure blood ; so it is shown in blue.
Of course the arteries near the heart are very much
larger blood-channels than those farther out, where
they divide as you see, into very many branches.

The veins are the vessels which gather
up the blood from all parts of the body
and carry it to the heart. All the veins which bring
dark, impure blood to the heart are represented by
blue vessels in the figure. This (31) large vein —
the pulmonary vein — carries pure blood; so it is
shown in red. The veins near the heart are very
much larger than those which are farther away.
There are valves in the veins to prevent the blood
from flowing or setting back in a wrong direction.

The capillaries are very fine tubes

The Capillaries. .. . ..* ,,

connecting the arteries with the

THE CIRCULATORY SYSTEM. 57

veins. Their name comes from a Latin word which
means a hair. It is difficult to imagine how numer-
ous these little capillary blood-vessels are, and bow
vw^ll they are distributed to all parts of the body.
You could scarcely prick your skin with a needle
anywhere without bringing some blood to the sur-
face ; you are sure to pierce some capillary and cause
it to leak.

In the capillaries are the landing

Blood Change

in the places where the little cargoes of

capillaries. building material, which have been
floated from the port of the heart through the arte-
rial rivers, are unloaded and distributed to the thou-
sands of little working cells, which are everywhere
busy in building or repairing the body. At some
places material for muscle is unloaded; at others
material for bone, nerve or finger nail is wanted. In
exchange for this new material which the capillaries
distribute to the body, they take back from the body
the material which has become old, worn out, and
unfit for use. The consequence is that the blood
which has come from the arteries into the capillaries
red and pure, leaves them and gathers in the veins,
dark and impure. It would be altogether unfit to
make another round through the body without being
purified; so the capillaries deliver it to the veins,
and these carry it to the heart, which drives it to the
lungs — one of the organs of another system — where
its worn-out matter is unloaded, and it is again made
fit to feed the body.

58 ELEMENTARY PHYSIOLOGY.

We will now trace and learn the circu-

of^Biood. lation or course of the bl°od in the
body. This diagram* in the center of
this plate will help us clearly to understand it. Here
the heart (32) is laid open, showing its inner cham-
bers and the valves between them. This large blood-
vessel (16) is one of two great veins which empty
the impure blood from the body into the right
auricle of the heart. It is called the ascending vena
cava, because it brings the blood from parts below
the heart. Here (15) is the other of these large
veins — the descending vena cava, bringing the
impure blood from the upper parts. A valve pre-
vents the blood from going back from the right ven-
tricle into the auricle above. Here (21) is the
pulmonary artery, which carries the blood from the
right ventricle to the lungs. The blood is driven
through this artery by the contraction of the muscle
of the ventricle. Coming back from the lungs to the
heart, the blood flows through this (23) pulmonary
vein, which empties into the left auricle. From here
it goes through a valve into the left ventricle. Now
notice the thick muscle of the left ventricle. When
this strong muscle contracts, the blood is forced out
through this (24) great artery — the aorta, which
branches out into many arteries and then into capil-
laries all through the body. It will be well for
you to learn and trace the course of the blood in this
way: Coming impure from the body, it flows into

* See plate showing "Formation and Circulation of the Blood."

THE CIRCULATORY SYSTEM. 59

the right auricle; then through the valve into the
right ventricle; then through the pulmonary artery
to the lungs ; then through the pulmonary veins to
the left auricle; then through the valve into the
left ventricle; then through the aorta into many
arteries ; then into the capillaries ; then ihto the veins,

which return it to the heart,

»

Three iHvis- ^nere are really three divisions of the
ions of the circulatory system. The first is the
course of the blood from the heart
through the body for building and repair. The
second is its course from the heart through the lungs
for its purification. The third is a special course of
a part of the blood through the liver. This is
called the portal circulation. We see here (18) how
several of these prominent veins gather the impure
blood from these lower organs in the body, and,
gathering into this (20) large vein, this blood is
thrown into the liver, where it is partly purified,
after which it is again collected by this upper (20)
hepatic vein, which turns it, as you see, into the large
(16) ascending vein, which goes to the heart.

Interesting The heart is' b? f&F' the strongest

Facts about the muscular part of the body. No

Circulation. . . , -, » .. -,

engine in the world, of its size, has
so much strength. It beats about 100,000 times per
day, 40,000,000 times per year, and in the life-time
of an octogenarian 3,000,000,000 times without a
stop! Its impulse is not only felt by its throbbing

60 ELEMENTARY PHYSIOLOGY.

on the walls of the chest; it may be easily felt at
several other points quite remote from the heart
itself, as, for instance, at the temples or at the wrists.
These impulses, as felt at these places, are called
the pulse. This index to the rate of the heart's
action is very convenient to the physician, since it
makes known to him at once any acceleration, retard-
ation or irregularity of the blood's circulation.

Health of the s^eady an(^ thorough work of the

circulatory organs of the circulatory system -is
very essential to life and health. Any
cause which tends seriously to increase or diminish
the normal rate of the heart's action is a thing to be
avoided. The ordinary quickening of the flow of
the blood, as in moderate exercise of the body, is
not only harmless, but healthful. Here, again, exer-
cise must be commended as a prime condition of
a healthy circulation. Any part of the body which,
from any cause whatever, remains comparatively
unused, will not be supplied by the circulatory sys-
tem with a sufficient quantity of pure blood to main-
tain its vigor. Such a part will therefore gradually
wither and die. It follows that we need that kind
of exercise regularly which will call into use all
parts of the body, and thus prompt the flow of blood
into every nook and corner of our physical structure.

OUTLINE.

THE CIRCULATORY SYSTEM.
( Central organ, the heart.
} Arteries, blood-vessels leading from the heart.

THE CIRCULATORY SYSTEM. 61

Veins, blood-vessels leading to the heart.
Capillaries, uniting arteries and veins.
Three divisions of the circulation:
From heart to lungs and back to heart, for purifi-
WHAT? •{ cation — pulmonary circulation.

From heart to body and back to heart, for nutri-

tion— systemic circulation.
From veins of digestive organs through liver, for

partial purification— portal circulation.

f Heart in chest, near middle.

WHEBE? ^ Arteries, veins and capillaries distributed through-
^ out the body.

f To carry pure blood to all parts of the body.
„ J To gather up useless or waste material and carry
'I it to the organs which remove it from the

(^ system.

QUESTIONS.

What can you say of the " wear and tear " of the body?

What is the object of the circulatory system?

What is the use of the blood?

What are the organs and vessels of the circulation?

Where is the heart situated?

About how large is the human heart?

Tell what you can about its purpose.

How many chambers has the heart?

Where is the right auricle?

Where is the right ventricle?

Where is the left auricle?

Where is the left ventricle?

What are the arteries?

What kind of blood do the arteries usually carry?

What are the veins?

Do they usually carry pure or impure blood?

Why do the veins have valves?

What are the capillaries?

62 ELEMENTARY PHYSIOLOGY.

What changes in the blood take place in the capillaries?
By what large vein is the blood from the lower body

brought to the heart?
By what large vein is the blood from the upper body

brought to the heart?
What prevents the blood from flowing backward from the

ventricle to the auricle?
What is the work of the pulmonary artery?
What of the pulmonary veins?
Why is the muscle of the left heart extra strong?
What is the aorta?
Now trace the course of the blood, beginning where it comes

impure to the right auricle.
How many divisions of the circulatory system?
Why does the heart send the blood to the lungs?
Why through all parts of the body ?

Why is a large part of the blood carried through the liver?
What is meant by the pulse?
What is the effect of exercise on the circulation?
May exercise become too violent?
How is the circulation affected in an unused part of the

body?
What is the best kind of exercise?

THE RESPIRATORY SYSTEM.

We have learned that the blood in its course
through the body is made quite impure and needs
to be repeatedly purified. For this purpose the
body is furnished with the respiratory system. The
chief organs of this system are the lungs, which lie
in the chest, close around the heart. Let us get a
clear and accurate idea how these important organs
are situated. ( Turn to the body manikin. ) Here is

THE RESPIRATORY SYSTEM. 63

a manikin of the body. We will remove the outer
muscles of the chest. Now, the ribs are before us.
Eemoving these, the contents of the chest are shown
precisely in their natural places. These (8, 9,) are
the lungs. The heart liesQimmediately under and
between them.

The lungs are very spongy and light,
fiie^m!™ ° being composed largely of air-cells,

whose walls are very delicate. These
air-cells are all connected with tubes (Turn to (25)
third section of lungs) and these tubes unite into
this one large air-passage (24) called the trachea
or wind-pipe. In the upper part of this wind-pipe,
which comes close up to the mouth, the instrument
of the voice, called the larynx, is situated. It is this
(21, 22, 23), enlarged portion of the trachea. The
exact structure of the larynx or voice-organ is shown
by special sections above the lungs in the body mani-
kin. This arrangement of these air-passages reminds
one of an inverted tree. The larynx or voice-organ
corresponds to the lower and thicker part of the trunk
of the tree ; the trachea to the trunk itself ; the branch-
ing air-tubes in the lungs to the branches and twigs,
and the air-cells to the leaves.

The pulmonary artery, which brings
use of the ^e jmpure blood from the heart into

jL4ii.ii.ir8*

the lungs, branches out (18) into many
small capillary tubes which wind among and around
these numerous air-cells. When the cells of the

64 ELEMENTARY PHYSIOLOGY.

lungs are filled with air, the oxygen of the air, in a
wonderful way, passes through the wall of the cell
and -the wall of the capillary and unites with the
blood. At the same time, impurities from the blood
pass through capillary wall and cell wall into the
cells and out through the air-passages with the
escaping breath. In this way the blood is renewed,
purified and brightened by the life-giving oxygen,
and starts vigorously off on another round through the
body.

Breathing is the act of the body by

Breathing. ^.^ ^ ^^ ^ fiUed ^.^ ^ ^

emptied again at proper intervals. This operation
is so important and essential to life, that it has been
entrusted to the performance of muscles of the invol-
untary kind, that is, such as are not dependent on
the direction of the mind. It is true, the will may
interfere with the work of these muscles, so that we
may suspend breathing to some extent. But it is
Nature's plan that this work should be committed to
faithful nerve-centers and muscles appointed for the
purpose. It is well that this is so, for, otherwise*
during sleep or other unconscious moments, when
the mind gives no direction to the body, breathing
would stop and life would end. Even when awake
and in health, in this very busy age, we might for-
get to breathe.

The scientific name for breathing is
respiration. That act of respiration
which brings air into the lungs is called

THE RESPIRATORY SYSTEM, 65

inspiration; that which drives the air from the
lungs, expiration. There are quite a number of
muscles concerned in these acts. When the lungs
are to be filled, these muscles expand the walls of
the chest so as to enlarge the space inside.
The air rushes in through the mouth, nose and wind-
pipe, and fills %the cells. Then a reverse action is
produced by the muscles. The chest contracts and
the air is forced out from the lungs by the same way
through which it entered, but robbed of its oxygen
and mixed with gases discharged from the body.

Between the chest and abdomen is a
iiTsM "scies!1" broad partition muscle called the dia-
phragm. This muscle is chiefly con-
cerned in ordinary, gentle breathing. When the
lungs are to be filled, the diaphragm moves down-
ward, pressing upon the contents of the abdomen
and enlarging the cavity of the chest, giving the
lungs room for full expansion, provided the act of
inspiration is unrestricted and complete. In expira-
tion, the diaphragm rises and diminishes the capac-
ity of the chest, forcing the air out of the lungs. In
forced breathing, the muscles between the ribs,
called the inter-cosfal muscles (6, rib section], take a
prominent part. These and other muscles also take
more or less part in ordinary breathing.

The inside of the chest is lined with a

delicate web called the pleura. This is

also spread as a covering over the lungs. It secretes a

OK THJt

UNIVERSITY

66 ELEMENTARY PH YSIOLOGY.

watery fluid which keeps the walls of the chest and
the surface of the lungs moist, and thus prevents
friction which would otherwise be produced in the
movement of breathing. The pleura is shown at (7
on section of the ribs). An inflammation of this
membrane is called pleurisy. When both pleura and
lungs are inflamed it is called pleura-pneumonia.

Health of the -^rom w^a* we Bave learned of the
Respiratory structure of the chest and the action of
the lungs in breathing, we can not fail
to see that the healthy and natural action of the respi-
ratory system requires perfect freedom of motion or
expansion of every part concerned in the vital act of
respiration. It is Nature's plan that every air cell
in the lungs should perform its appointed part with
all the rest, at every breath. If the habit of breath-
ing, full and deep, while the chest is perfectly free
to expand and the body is in erect or straight posi-
tion, is well formed, every lung-cell will be filled at
each inspiration. But if the chest is in any degree
restricted and compressed, the lungs will be but
partly filled, and many of the air-cells will lose their
elasticity, and finally become utterly useless. Such
an injurious interference with the natural expansion
of the chest may be produced by habitual unnatural
positions in sitting or walking, or by wearing the
clothing too tight about the body.

We have learned that the flow of blood
through the vessels of the circulatory

THE RESPIRATORY SYSTEM. 67

organs is much quickened by exercise. So the rapid-
ity of the flow of the blood through the lungs de-
pends very much on the degree of our bodily activity.
When we lie in bed, for instance, the circulation goes
on very steadily, and our breathing is performed
very moderately and quietly. But as soon as we
arise and move about, both the circulation and respi-
ration are quickened. The more vigorous the activ-
ity of the body the more air is drawn into the lungs
to purify the greater quantity of flowing blood. The
chest muscles act more strongly and every cell in the
lungs is inflated. All this tends to produce pure
blood and active lungs, and, consequently, good
health.

The quality or purity of the air which

t^Bre'ath.0* we breathe is quite as important as the
quantity which we inhale. We have
learned that the oxygen, which is one of the elements
or gases which compose the air, is taken from the
lung-cells to unite with the blood. This alone would
make the breath which is given out impure because
of its having been robbed of its oxygen. But the air
which is forced out from the lungs is made much
more impure by the gases which come from the im-
pure blood of the body. These gases escape from
the lungs at every breath. It is plain that if we
breathe in a close room or in a confined body of air,
every breath adds to the degree of impurity of the
air, so that the latter becomes more and more unfit
to breathe. It becomes unfit to sustain life, not only

68 ELEMENTARY PHYSIOLOGY

because it is robbed of the life supporting oxygen,
but because one of the gases which are expelled from
the body, by the breath, acts like a poison when it is
inhaled (re-breathed) again.

Ventilation means the furnishing of the

Ventilation.

needed supply of pure air. Nothing is
more important in the line of hygienic or health pre-
cepts than this, that we should avoid the breathing
of air which has been made impure by the breath.
To avoid this, it is necessary to have, at all times,
a proper interchange between the air of a room and
the pure, free air without. No person can remain
long in a closed room without being injured by his
own breath. There must be a place of escape for
the impure air and a place of entrance for the pure
air. Since impure air rises toward the top of a
room, it escapes best from the opening of a window
at the top, while pure air enters best through an
opening lower down. But without attempting to
describe any of the numerous plans of ventilation,
let this precept suffice: Get from the abundance of
pure air which God has provided, as Etuch as you
can at every breath, and avoid, as a poison, the inha-
lation of impure air.

THE VOICE.

The organs of the voice are so closely connected
with the respiratory system that we will give a
brief description of them here.

THE RESPIRATORY SYSTEM. 69

The chief organ of the voice is the larynx.

This is really an expansion of the upper

The larynx. , „ . . , , ..

end of the wind-pipe, as already seen.
The prominent point on the front of the neck, com-
monly called "Adam's apple," is a part of the larynx.
The cartilages of which the larynx is mainly composed
form a sort of box, along whose two inner sides are
stretched two membranous chords called the vocal
chords. These come more or less closely together at
the middle of the larynx, the slit or chink between
them being called the glottis. Through this glottis
every in-going and out-going breath ordinarily passes
silently. But when the muscles which regulate the
vocal chords tighten up these chords, while air is
being expelled from the lungs, a sound is produced,
either high or low, according to the degree of ten-
sion, or tightness, to which the vocal chords are drawn.
If you have learned to sing up and
down the eight tones of the musical
scale, you may easily perform an experi-
ment on the action of the muscles which control the
tension of the vocal chords. Sound slowly the sylla-
bles up and down the scale. You will feel a change
in the contraction of the larynx muscles at every
change of tone. Going up the scale, that is, to a
higher and higher pitch, you will feel a tightening
action of these muscles: coming down the scale to a
lower and lower pitch, an opposite effect will be felt.
The action of the breath on the vocal
chords which has just been described,

An Experi-
ment.

70 ELEMENTARY PHYSIOLOGY.

produces vocal sounds of different pitch. Their
loudness depends upon the degree of force with which
the breath is forced through the glottis. But this is
not speech. To produce the articulate sounds of
language, the sounds which are made by the vocal
cords are very much modified and variously shaped
by the changing position of tongue and mouth, which
are produced in speaking. This is illustrated in
every word we speak, and you will find it to be an
interesting experiment to utter slowly the sounds
which compose some word, while noticing the changes
which you make in the position of your mouth and
tongue.

OTTTLINE.

THE HESPIRATORY SYSTEM.

Lungs, very light and spongy, chiefly composed of

air-cells.

Trachea — commonly called wind-pipe.
Larnyx — upper part of trachea, and organ of the
WHAT ' voice.

Air-passages through mouth and nose.

Chief respiratory muscles — the diaphragm and

inter-costal muscles.

f Lungs — in middle of the chest.
J Trachea — between throat and lungs.
ERE . •< Diaphragm — between chest and abdomen.
[^ Inter-costal muscles— between the ribs.

f To furnish oxygen to the blood.

WHY / j rjiQ 6Xp6i impurities which come from venous
blood.

THE RESPIRATORY SYSTEM. 71

QUESTIONS.

What is the use of the respiratory system ?
What are the chief organs of respiration ?
Where are the lungs located ?
Describe their structure ?
What is the trachea ?

What vessel brings the blood from the heart to the lungs ?
Tell what takes place in the lungs.

Is the act of breathing performed by voluntary or involun-
tary muscles ?

Why is this a wise provision ?

What is meant by inspiration ? Describe the process.
What is meant by expiration? Describe the process.
What is the lining membrane of the chest called ?
What is the benefit of full and deep breathing ?
What are the consequences of cramping the chest ?
What is the effect of exercise on the lungs ?
How is the air made impure by breathing ?
Tell what you can of the necessity of ventilation.
Where are the vocal cords ?
How are the sounds of the voice produced ?
How is the pitch of the voice varied ?
How are the louder tones produced ?
What other organs assist in forming the sounds of speech ?

THE DIGESTIVE SYSTEM.

Where does the building and repairing material,
which is delivered to all parts of the body by the
blood, come from ? How is it prepared and how
does it find its way into the blood-vessels of the cir-
culatory system ? These are some of the physiolog-
ical queries which come to us now.

72 ELEMENTARY PHYSIOLOGY.

The matter of the body all comes from

fto^f JBtort!"* our foocL To Provide our bodies with
such material, of good quality and of

proper quantity, ought to be the main object of our
eating. Not all of the food matter which we eat is
useful in the body. So the means of separating the
useful from the useless is necessary. Then, again,
the useful part? of our food must be very much
changed before they can be used by the building
cells of the body. So the means for its proper prep-
aration must be furnished. The system whose or-
gans prepare the needed elements of tho food for
the blood, and separate the useless from the useful
portion, is called the digestive system.

The preparation of food material for
*^e blood requires many operations.
So the digestive system has a greater
number of special organs than any other system of
the body. We have seen how the movements and
work of the circulatory organs depend upon the
strength and prompt action of the muscles of the
heart; also, how the respiratory system depends upon
the muscular system in the steady and proper action
of the breathing muscles. So, here, as we study the
processes of the digestive system, we shall find how
its work depends upon the muscles which are assigned
to the duty of producing the necessary movements of
its organs. Even the muscles of the arm and hand
perform the very first act in the process of feeding
the body, in properly bringing the food to the mouth-

THE DIGESTIVE SYSTEM. 73

The whole process of preparing food material for the
blood is called digestion. The first step, that is,
bringing the food into the mouth, is called prehen-
sion.

The second step in digestion is masti-

Teeth °* the cation' This is performed in the mouth
by the teeth. The mouth and the teeth,
as used in chewing or masticating the food, have
been called the mill of the body. The grinding in
this mill is done by the muscles which move the
jaws so as to produce a cutting, crushing or grind-
ing effect upon the food by the teeth.

There are thirty-two teeth in the full

Teeth*1" °f se^ °^ a grown Person- These are set
in sockets of the upper and lower jaw-
bones— sixteen in each jaw. Eight front teeth —
four in each jaw — are called incisors, or cutting
teeth. On each side^ of these incisors — above and
below — is a canine tooth. The two upper canines
are often called eye-teeth, and the lower canines,
stomach-teeth. These twelve teeth — eight are incis-
ors and four canines — separate or bite off a proper
portion from the food which is brought to the mouth.
Next to the canines are two bicuspids, on both sides
of each jaw. Bicuspid means having two roots.
Then follow, as back teeth, three molars or grinders
on both sides of each jaw. These twenty teeth —
eight bicuspids and twelve molars — do the work of
crushing or grinding the food to a proper degree of
fineness.

74 ELEMENTARY PHYSIOLOGY.

As we have already learned, a tooth
e °f

a Tooth.

°f is not a bone. It does not belong to

the skeleton. The teeth are instru-
ments or organs of the digestive system. The
structure of a tooth is an interesting study. To help
us understand it, we are provided, in the Anatomical
Aid, with the means of completely dissecting — that
is, separating into its parts, the structure of a tooth.
In the manikin of a tooth, the little projecting
ridges at the top (1) are called tubercles. The por-
tion above the gum (2) is called the crown. This
is covered by a thin layer of enamel, the hardest
material in the body. The tooth is mainly composed
of a substance called dentine, or ivory (9). At (6)
and (7) the roots of the tooth are shown. At (12)
blood-vessels and nerves are seen to enter into
the tooth. When an opening occurs in the body of
the tooth, from decay, this nerve is exposed to the
air and the action of food particles, and toothache
is the result.

The third step in digestion is insaliva-

Work of the

salivary lion. Really, mastication and insahva-
<• lamis. £.Qn are performed at the same time.

While the food is being chewed by the teeth, a liquid
is mixed with it in the mouth. This liquid is spe-
cially prepared for this purpose, from the blood, by a
number of organs called salivary glands. By the
way, let us not forget that all the substances of the
body are prepared from the blood. A gland is an
organ which secretes — which means separates — some

THE DIGESTIVE SYSTEM. 75

special or peculiar substance from the blood. So,
one of the glands of the eye secretes tears, and the
salivary glands secrete saliva. Three pairs of these
glands are quite prominent. The largest pair is
just below and in front of the ears. The second pair,
in size, lies under the jaw-bone, and the third pair is
under the tongue. These glands, between meals,
furnish enough saliva to keep the mouth moist. But
when food is taken into the mouth and chewed, or
even at sight of something tempting to the taste,
they furnish it in great abundance. It not only
moistens the food so that it may be easily swallowed,
but it also begins the process of changing the food
material.

The fourth step in digestion is swal-

Work of the

Pharynx and lowing. This is a much more familiar

Oesophagus. ig the gci_

entific name for the same act. When the food has
been properly prepared in the " mill of the mouth,"
it is swallowed, or sent to the stomach. The cavity
back of the mouth is called the pharynx. Between
the pharynx and the stomach (refer to body manikin)
is this tube (35) called the oesophagus. By the
action of the muscles of the pharynx and the oesopha-
gus, the food is moved into the stomach. This is
deglutition.

We have now traced the course of the

$tonia°h th° ^ooc^ *n*° *ne ma^n organ of digestion —

the stomach. Here its greatest change

is to be produced. The position of the stomach

76 ELEMEN TARY PHYSIOLOGY.

should be well understood. Observe it carefully in
this manikin (31). The stomach has three coats or
walls. The outer coat is thin and smooth, and fitted
for the protection of this organ in its contact with
other organs. The inner coat — called the mucous
wall — contains many little glands or cells, which
secrete a substance which is very important in the
process of digestion. It is called the gastric juice.

When food comes into the stomach the

intermixing is made quite thorough by
the action of the muscles which compose the middle
coat of the stomach. As long as there is food
within it, these muscles keep up a churning motion
of the organ. The result of the action of the gastric
juice is that the food is very much changed in its
nature and appearance. It is now called chyme, and
the change which has been produced in the stomach,
chymification.

At the right end or discharging open-
ing of the stomach is placed a muscular
valve called the pylorus. This name
means gate-keeper. The pylorus is a door-keeper of
the stomach. Such portions of the contents of the
stomach which have been properly changed into
chyme, it allows to pass out, but refuses passage to
other portions. Much depends upon the faithfulness
of this pyloric muscle. When from any cause it
loses its power, or refuses to act, the food escapes

THE DIGESTIVE SYSTEM. 77

from the stomach before it is prepared to enter the
intestines, which is a form of indigestion which soon
destroys life.

The Liver, as the manikin shows, is a
the i!iver very large organ overlying the stomach.

It weighs from three to four pounds.
It is both a blood-purifying and a secretory organ.
As a secreting organ, it performs its part in the
process of digestion by furnishing a substance called
bile, which it sends through a duct or tube into the
duodenum, or upper part of the small intestines,
where it aids in further change of the chyme
which has just passed into the intestines from
the stomach.

Back of the stomach lies the pancreas

^an^eL1.116 (59)' ™S °rgan furnishes a fluid

called the pancreatic juice, which is also
brought into the duodenum. The action of the bile,
the pancreatic fluid and the intestinal juice, is to
change the chyme into chyle, and to separate the
useless or waste portion of the food. This waste
portion is carried out of the body by way of the
intestines, and the useful portion, having undergone
all the processes of digestion, is now ready to be
given to the circulatory system for transportation
to every point of demand. How the chyle is trans-
ferred from the digestive organs into the blood will
be shown in the next chapter.

78 ELEMENTARY PHYSIOLOGY.

Perhaps no system of the body is more
Health of the * J

Digestive carelessly or more frequently abused

than the digestive system. No system
of the body brings back upon the abusing offender
a severer penalty of discomfort. Proper digestion is
the very first condition of good health. Hence the
hygienic principles referring to this system should
be carefully learned and regarded.

The injury resulting from eating too

K Too
Fast.

Eating TOO £agt comes chiefly from this, that the

processes of mastication and insaliva-
tion cannot be properly performed. Unless the
food is properly chewed, and thoroughly mixed with
saliva, its digestion in the stomach will be either
much retarded or left incomplete.

The capacity of the stomach is limited.

; Too
Much.

Eating? TOO If it ip overloaded, it can not thoroughly

digest its contents. Besides, the gas-
tric juice is also limited in quantity, and will not
completely change into chyme more than a proper
portion.

Between the digestive operations of the
stomach, it needs intervals of rest. If
food is taken too frequently, it loses its
vigor, and soon fails to perform its work in a healthy
manner.

Some articles ofj food, though very
tempting to the taste, are very "trying "
to the stomach. It is plain, that, if

=39

Exercise.

THE DIGESTIVE SYSTEM.

these are too frequently eaten, the stomach's action
will be greatly impaired. If eaten at all, they
should be sparingly mixed with more digestible
food.

Gentle exercise is very helpful to diges-
tion. But violent exercise, either just
before or after a meal, is quite as injurious. A
cheerful state of mind is very helpful in keeping up
a healthy action of all the digestive organs.

OUTLINE.

THE DIGESTIVE ORGANS.

Teeth— 32 in full set.

Salivary Glands— three pairs.
; Muscles of Pharynx and (Esophagus.
-j Stomach.

Liver.

Pancreas.
L Intestines.

Teeth — in sockets of jaw-bones.

Salivary Glands — located about the mouth.

Pharynx and oesophagus — funnel and tube —
between mouth and stomach.

stomach— under diaphragm in abdomen.

Liver— overlying the stomach.

Pancreas— lying back of the stomach.
^ Intestines— filling lower abdomen.

Teeth- to masticate the food.

Salivary Glands— to furnish saliva.

Muscles of pharynx and oesophagus move the food
from mouth to stomach.

Stomach— to change food to chyme.

Liver — to furnish bile.

Pancreas — to furnish pancreatic juice.

Intestines— to complete the work of digestion and
separate the chyle from the waste matter,

WHAT?

WHEBE?

WHY ?

80 ELEMENTARY PHYSIOLOGY.

QUESTIONS,

From what does all the body material come?

What processes are necessary to fit food for body nourish-
ment?

What is the name of the system which performs these pro-
cesses?

What is the first act in the process?

What steps take place in the mouth?

How many teeth in a full set?

Name the different kinds of teeth.

How is the food conveyed from the mouth to the stomach?

Describe the work of the stomach.

By what means is the gastric juice well mixed with the food?

What is the food, as it leaves the stomach, called?

Describe the action of the pylorus.

What does the liver furnish for the work of digestion?

What is furnished by the pancreas?

What is the chyle?

What are the consequences of eating too fast?

What results from over-eating?

What from eating too often?

What from eating indigestible food?

What are the effects of exercise on the digestion?

THE ABSORPTIVE SYSTEM.

In previous lessons we have learned how food is
prepared by the organs of the digestive system and
reduced to a fluid state. Let us also recall what we
have learned of the circulatory system; how the
blood is constantly making the circuit of the body,
carrying food to every tissue.

The sixth plate of the Anatomical Aid shows most
admirably all the organs and parts concerned in the

THE ABSORPTIVE SYSTEM. 81

two processes just referred to, and a careful stu^y
of this plate will enable us to understand their rela-
tion to and connection with each other. How, then,
does the digested food get into the circulation?
What provision is made for transferring it from the
alimentary canal to these blood-vessels? To answer
these questions, we must first study how food is

absorbed.

The food in its liquid form must in the

Absorption.

first place be removed from the stom-
ach and the intestinal tube. This is accomplished
by a process called absorption. This work may be
more easily comprehended by first referring to a
similar process constantly going on in vegetable
growths. Planted in good soil and supplied with
water, a plant will send out its small rootlets, whose
little mouths will drink in (absorb] mineral sub-
stances from the soil dissolved by the water. This
liquid plant-food is carried by the sap (vegetable-
blood) up the trunk or stem to nourish the parts of
the plant. There is a similar provision for taking
up the liquid food from the alimentary canal. There
are little rootlets provided for this work whose action
resembles that of the root-fibers of the plant.

The inner wall or coating of the small
vnii8tinal intestines has a velvety or plush-like

appearance. This is due to the myri-
ads of little hair-like projections, which hang down
from the inner walls and point toward the center of
the tube. These small cones or fingers are called mill.

82 ELEMENTARY PHYSIOLOGY.

They are very numerous, covering the intestinal
membrane as with a coat of hair. The word signi-
fies hair-like bodies. These villi, which dip into the
liquid contents of the alimentary canal, are not
themselves the absorbents; but they contain small
rootlets which take up the food and start it on the
way toward the heart.

In each villus (singular of villi) there
TWO classes are two kinds of little workers gather-

of Absorbents . _... . . , » f. -, ,.,

in the villi. ing up different kinds of food particles
from the liquid mass in the intestines.
These are known as blood-vessels and lacteals, and
are the starting points of two different routes by
which the food is carried to the heart and into the
circulation.

The blood-vessels or veins are arranged
veins in the aroun(j the center of the villus, form-
ing a sort of net- work. They all unite
and form one large vein, plainly shown here on the
Aid (20). This vein is called the portal vein.

portal The route by which the blood and food

circulation, carried by the veins reach the heart
constitutes the portal circulation, which we will
now consider a little more fully. The portal vein
(20) empties its contents into the liver (33) from
below, and divides and subdivides, finally forming
the capillaries of the liver. The structure of the
liver is shown by the Aid at (18) (under microscopic
structure of the textures). In the liver an important

THE ABSORPTIVE SYSTEM. 83

process takes place. The bile is secreted from the
venous blood, and stored up in the gall-bladder, to
be used when needed in the digestion of food. The
blood, after being robbed of its bile and changed in
other respects not well understood, is again collected
and carried upward by the hepatic vein (20) and
emptied into the lower vena cava (16), which in turn
pours it into the heart, as shown here by the Aid.
This completes the portal circulation.

Now let us go back to the same start-

RouteCCOnd *n£ P°in^ and trace other portions of

the digested food by another route;

but which will ultimately lead to the same cavity of

the heart.

At this point we should observe how nicely every
organ of the body is adapted to perform its own
specific work. The blood-vessels spoken of under a
preceding head take up from the stomach and intes-
tines only certain portions of their contents, to do
which, they seem especially adapted. Other portions
are absorbed by the lacteals, which seem to be par-
ticularly suited for this purpose.

Extending lengthwise through the cen-

«Te vim ln ter of eacn little villus> surrounded by
the meshes of the small veins just
described, is a single minute duct or rootlet called a
lacteal. Lac means milk, and it is owing to the
milk-like appearance of their contents that the term
lacteal is applied to these vessels.

84 ELEMENTARY PHYSIOLOGY.

As ID the case of the blood-vessels,
Vesse^Tand wnich are the beginnings of the portal
Lymphatic circulation, so the lacteals unite and

finally form the thoracic duct (10).
Just as small creeks flow together and form larger
streams, so the lacteals form chyliferous vessels,
which are shown here at (7) on the Anatomical Aid.
These vessels carry the chyle absorbed by the lac-
teals through numerous glands called lymphatic
glands (6), and finally empty it into the chyle recep-
tacle, which is seen here at (9).

The chyle receptacle is a sac-like expan-

Thorarie g|ou Q£ ^ lower en(J of t}ie tJloracic

JLPUft.

duct, which is about as large as a slate
pencil or goose quill. The direction in which it
carries the chyle is very plainly seen by referring to
the Aid. It passes upward in front of the spinal
column and behind the oesophagus (2). At its upper
end it bends forward and downward, something like
the crook of a walking cane, and pours its contents
into the left subclavian vein. From this point the
chyle passes into the innominate vein (14), and then
through the upper vena cava (15) into the right
auricle of the heart.

Thus we have traced the different sub-
Been Done.

What Has stances of which the digestive food

is composed by different routes to the
same cavity of the heart, there to mingle with each
other, and with the impure blood collected from all

THE ABSORPTIVE SYSTEM. 87

5. Being fatty substance, it is absorbed chiefly by
the lacteals.

6. The chyliferous vessels (7) carry it through
the lymphatic glands (6) into the chyle receptacle (9).

7. The thoracic duct (10) empties it into the
subclavian vein at 11, by which it reaches the right
auricle of the heart

8. From this point the two kinds of food travel
together toward the outposts of the body, carrying
nourishment wherever needed.

THE LYMPHATIC VESSELS.

Besides the blood which is found cir-
culating in all parts of the body, there
is another fluid, almost colorless in appearance,
which is also found widely distributed throughout
the system. This fluid is called lymph, which sig-
nifies transparent fluid. In composition the lymph
closely resembles the plasma of the blood, and con-
tains minute bodies or corpuscles resembling the
white corpuscles of the blood; these are called
lymph globules or lymph corpuscles.

This fluid is supposed to be mostly
S'm™0*" worn-out materials gathered from all

parts of the body. It consists probably
of portions of blood- ingredients which have oozed
through the walls of the arteries, veins and blood-
capillaries, together with certain products of the
combustion which takes place in the body. These sub-
stances are gathered up by tiny vessels, and, after

88 ELEMENTARY PHYSIOLOGY.

being worked over in a manner not well understood,
they are capable of further use in the body. Thus
we see a wise economy in allowing nothing to go to
waste which can in any way be put to further use.
This reminds us of the economy practiced in sifting
coal ashes taken from our stoves and furnaces, sav-
ing therefrom such partly burned coal as may be
capable of giving off more heat if put into the fire
again.

The vessels which carry the lymph just
lymphatics described are called lymphatics. They

are more delicate in their structure than
the veins and arteries and permeate every part of the
body. Wherever blood capillaries are found, there
lymph capillaries are also found, though on account
of their minute size they can not be seen until injected
with mercury or some colored fluid. They vary in
number with the variation of the number of blood
vessels.

The functions of the lymphatics of the

system may be regarded as similar

m of to those of tiles, or drain pipes, which
farmers so frequently lay in wet,
swampy lands for the purpose of carrying off the
surplus water. The water soaks into these tiles,
which carry it off under ground, thus drying the field.
Likewise the surplus fluids which collect in all parts
of the body are absorbed by the lymphatics — the
drain pipes of the body — which unite, forming
larger vessel s, which empty into the thoracic duct, with
the contents of which the lymph reaches the heart.

THE ABSORPTIVE SYSTEM. 89

In all parts of the system the lymphat-
ics pass through small bodies called

phatic <; lands.

lymphatic glands, which vary in size
from that of a pin-head to an inch in diameter. It
is not definitely known what the function of these
glands is; but it is probable that they renovate or
work over the waste and surplus material brought
to them by the lymphatics, and that the lymph
globules originate in them. Whether this is true
or not, there can be no doubt that these glands are
essential to health; because, when they become
hardened or inflamed, as is often the case in persons
of a scrofulous tendency, health fails and the patient
grows thin and emaciated, even though his diet may
be of the proper kind and quantity.

The lacteals, which we have considered

The Lacteals, . m '

a Part of the in connection with the absorption of the
cs" food from the alimentary canal, are a
part of the lymphatic system. They constitute that
portion which begins in the villi of the intestines.
When the process of digestion is completed, they
serve as drain-pipes, like the lymphatics in the system
at large. Their special work, however, is that in
connection with the absorption of fatty food through
the walls of the intestines.

We have learned how the blood "cir-

TheL,ymphat- , . „ ,

ics compared culates; how it starts from the heart

e , and after making the complete circuit,

Blood- Vessels. '

is brought back to the heart again. We

90 ELEMENTARY PHYSIOLOGY.

have learned also that the blood-vessels both give
off tissue-making substances and take on waste and
worn-out material, which they carry away. In con-
trast with this the lymph does not "circulate." It is
carried toward the heart, where it enters the life-
giving stream — the blood. In the lymphatic system
there are, therefore, no vessels to correspond with
arteries. Again, the lymphatics collect worn-out tis-
sues, etc., but give nothing in return.

The work of the lymphatics is not Con-
Other Func- J . r

tions or the fined to the absorption of food from the
Lymphatics. intestineg an(j collecting surplus and

waste materials from the system in general. Certain
other phenomena, all of which are of interest to us,
are due to the absorbing power of these vessels. For
instance, when a poisonous substance is placed upon
the skin the lymphatics at once absorb it and carry
it into the circulation. The lymphatics of the lungs
take in the poison of disease and diffuse it through-
out the system. When the appetite fails during
long-continued illness, life is sustained by the uncon-
scious consumption of one's own flesh, which is
absorbed by the lymphatics and carried out into the
circulation.

In a similar manner, as we will learn further on,
the poisonous nicotine of tobacco is absorbed in the
lungs and the system poisoned. Thus we see that
these vessels, which are ever active, take up, indis-
criminately, foods, poisons, medicines, or the waste
of worn-out material

THE ABSORPTIVE SYSTEM.

91

In concluding our consideration of the

Suggestions * .

to the absorptive system, let it be suggested

Teacher. tliat the Anatomical Aid be constantly
referred to. In all topics discussed, it will be an
Aid indeed, and the work be made incomparably

more effective.

OUTLINE.

Food is absorbed.
It is conveyed to the circulation.
WHAT? -J Surplus and worn-out tissues are collected.

They are renovated and prepared for use, and are
again thrown into the blood to be used.

In the walls of the alimentary canal.
In the system at large.
WHERE? ^ In the tissue of the skin.
In the cells of the lungs.
Wherever blood-vessels are found.

WHY? -| To collect and transfer material.

QUESTIONS.
What is absorption?
How do plants illustrate the manner in which food is taken

from the intestines?

What is there in plants to correspond with blood in animals?
What gives the lining membrane of the intestines its smooth,

velvet-like appearance ?
What do the intestinal villi contain ?
Describe their structure.
What is the portal vein ?
Trace the food absorbed by the veins, from the intestines to

the heart.

How is the blood changed in its passage through the liver ?
Where is the hepatic vein ? and what is its function ?
What are the lacteals ? What is their function ?
Of what general system are they a part ?

9 2 ELEMENTARY PHYSIOLOGY.

Through what glands do they pass ? Into what do they

empty ?

What is chyle ? Why are the lacteals so called ?
What are the chyliferous vessels ?
Describe the thoracic duct. Locate it.
What is the chyle receptacle ? Describe it.
Explain assimilation. Where does it take place ?
Trace a mouthful of food from the mouth to the tissue in the

body.

What is lymph ? What does it resemble ?
What are 1;, niph globules ?
Explain the origin of lymph.
What vessels carry it ? Describe fully the action of the

lymphatics.

With what may they be compared ?

In what respects do the lymphatics differ from the blood-
vessels of the general circulation ?
What is the difference between lymph and blood ?
Explain how the lymph vessels constitute a drainage system

of the body.

Whither is the lymph carried ?
What are lymphatic glands ? Describe them.
What effect have they upon the general health when they

become diseased or hardened ?
Why should we be careful not to touch poison ivy ?
What danger is there in breathing the air of a sick chamber?
When a squirrel or other animal hibernates, on what does

it subsist ?
Why is medicine sometimes injected under the skin, and

how is it rendered effective ?
Name all the vessels which constitute parts of the absorptive

system.

THE EXCRETORY SYSTEM. 93

THE EXCRETORY SYSTEM.

It will be remembered that the material collected
by the lymphatics is principally such as is capable
of being worked over in the little workshops, the
lymphatic glands, and used again as building mate-
rial of the body.

There is, however, much waste matter which can
not be thus elaborated for further use in tissue-
building; and yet some of this material is taken
from the blood by organs adapted to this particular
purpose, and converted into substances essential to
some of the vital processes. Other parts are fit for
nothing whatever, and must be expelled from the
system, because, if allowed to remain in the blood,
they would not only be useless, but an actual poison
to the system.

The organs whose function it is to take

The Excre-

tory from the blood such substances as can

^^ ^Q utilized again in the body -build-
ing process, but which must either be changed into
some other substance, or expelled from the body,
are the lungs, liver, kidneys and skin. Each of
these is suited to take from the blood its own kind
of impurities, and either elaborate them into some
usable substance or start them in their course lead-
ing from the body .

94 ELEMENTARY PH YSIOLOGY.

THE

The excretory functions of the lungs

Impurities J

Thrown off (Turn to manikin of the body, 8, 9.)
e Lungs. jiave been referred to under Respira-
tion, and their structure there explained. The pure
air, taken into the lungs, gives up its life-giving
oxygen, and in return becomes heavily loaded with
carbon dioxide, or, as it is more commonly called,
carbonic acid gas.

The chief of the excretions fcrom the
moxide lungs is carbon dioxide. It is a re-

sult of the union of the oxygen of the
air inhaled, and carbon from the tissues of the body.
This compound will not only fail to support life,
but is an actual poison.

The destructive nature of this gas is
illustrated in many ways. As for in-
stance, if a man goes down into a well
and is overcome, becomes unconscious and helpless,
it is this gas which causes his condition. It is of
the same kind as that which is thrown off by the
lungs, is colorless, and is heavier than air, and conse-
quently settles to the floor, or into cellars, wells, etc.
Therefore it is safer to sleep on a bed than on the
floor, since this deadly gas settles, during the night,
on the floor.

As it will not support life in man and animals, so
it will not support combustion, or burning. Hence,
if it should become necessary to go down into a well,

THE EXCRETORY SYSTEM. 95

it would be advisable to first lower into it a lighted
candle. If the candle continues to burn, it may
be concluded that the well is sufficiently free from
carbon dioxide to enter it with safety.

That the lungs expel a gas which is
Test of the identical with that' which collects in

i>reuin.

wells may be illustrated by breathing
into a glass jar, after having held the breath in the
lungs for some time. If a lighted taper or wax
candle be lowered into the jar containing this
exhaled breath, it will go out, thus showing the
absence of pure air and the presence of carbonic
oxide. Again, to show that other substances, such
as particles of animal matter, are contained in air
once breathed, let the contents of the lungs after a
full inspiration be breathed into a bottle and corked
up. The effete matter excreted with the breath will
decompose and soon give off an offensive odor. Thus
we may understand the need of ventilation already
mentioned. We can understand how the excretions
from the lungs soon make the air in a closed roojn
unfit for breathing, causing drowsiness and headache.
The especial need of well- aired school-rooms is
therefore urged for the consideration of teachers
and pupils. Let pupils make the simple tests men-
tioned and see for themselves the importance of
proper ventilation.

Besides what has already been men-

tioned' the luns8 take from the blood

a watery vapor which is ordinarily not

96 ELEMENTARY PHYSIOLOGY.

visible, but in cold weather is condensed and collects
on the windows, or can even be seen as it comes with
the breath from the nostrils or mouth. It is chiefly
the vapor of alcohol which is expelled from the
lungs of a person who has used strong drinks, and
his breath thus tells the tale of his indulgence. It
has been carefully estimated that about one or one
and one-fourth pounds of water is daily given off
with the breath of a man.

THE LIVER.

The liver, and its connection with the
tor "oif^an*" Process °^ digestion and also the portal

circulation have been spoken of else-
where. But it must also be considered as an excre-
tory organ. Its function is not merely to secrete
from the blood a fluid needed in the process of
digestion, but by so doing it acts as a blood purifier.
It is a well established fact, that, in case of a diseased
liver, when that organ fails properly to perform its
work of secreting the bile, which thus remains in the
blood, a disease known as jaundice ensues, and, if
this disease is hot checked, the person dies with
symptoms of poisoning.

THE KIDNEYS.

The kidneys are two bean-shaped bodies, a little
more than half as large as the closed fist. They
are located in the back part of the abdominal cavity,
one on each side of the spinal column. Their shape,
size, appearance, color and structure are very

THE EXCRETORY SYSTEM. 97

plainly shown by the Anatomical Aid (manikin of
the body). These dark-colored little glands have a
very important function to perform. They cannot
delegate their work to any other organ of the body,
as is the case with some of the other glands. They
alone can perform the work assigned them. Hence,
when diseased, their work is not done, and sickness
ensues.

The particular and only work of the

Work of the i • i • P 111

Kidneys. kidneys is to separate from the blood
brought to them, a substance called
urea. This is a very poisonous matter, which, if
not removed from the body by the healthy action of
the kidneys, will accumulate, and finally cause
death.

The renal arteries (g) constantly carry

The Kidneys . , . .. V°/ , , i

at work. to the kidneys a portion of the blood,
which passes through the capillaries of
the kidneys, as seen by turning back the first sec-
tion of the right kidney of the manikin. The
blood is again collected by the veins, and conveyed
through the renal vein (h) to the large veins lead-
ing to the heart. In the capillaries of the kidneys
the blood loses its watery part, which carries, in so-
lution, impurities called urea. This watery fluid
soaks through the thin capillary walls, is collected
and conveyed by two tubes (56), called ureters, to
the bladder (57), whence it is expelled from the
body.

98 ELEMENTARY PHYSIOLOGY.

Difference be-

As has been shown, the bile, secreted

tween sec-re- f rom the blood, is utilized in the diges-
tions of the
Liver and tive process. But the secretions

Kidneys. Q£ ^Q kidneys are poisonous to the
system, cannot be used in any process whatever,
hence must be at once removed from the system.
Thus the kidneys are exclusively excretory organs.

LESSONS FROM THE MICROSCOPE.

There are about us myriads of wonder-
ful creations which cannot be perceived
by our unaided senses. Our sense of sight is not
sufficiently acute to see the countless numbers of
minute living bodies which throng every drop of
water taken from a pond. We can not see the tiny
corpuscles which float in the blood and give it its
color, just as indigo dissolved in water will give it a
blue color. Many persons know nothing of the
wondrous beauty with which God has clothed the
insects which swarm about us. With the unaided
eye we see no beauty in the so-called dust which
covers the wings of our moths and butterflies. But,
when we call to our aid proper instruments, made
for the purpose, the dust on the • wings and body of
the butterfly is at once transformed into beautifully
formed scales, of brillian: rainbow colors and the
most perfect shape and structure. The instrument

LESSONS FROM THE MICROSCOPE. 99

constructed to aid us in seeing things which are too
small for us to see without this apparatus is the
microscope. Its structure and principles upon which
it operates, can not here be explained. Let it be
sufficient to say that the microscope is a combina-
tion of glass lenses so arranged as to make things
seen through it much lai-ger. If you take your
grandmother's spectacles and hold them just right,
objects seen through the glasses will appear larger.
In a similar way and for a similar purpose the glasses,
or lenses, of a microscope are used, only that the
microscope makes a much greater difference in the
apparent and real size of objects seen through it.

MICROSCOPIC STRUCTURE OF THE TISSUES.

As the minute scales of the butterfly
scope as an can n°t be satisfactorily examined with-
Ajd m ou^ ^Q micrOscope, so the proper and

successful study of the different tissues
of the body requires the aid of this instrument. And
since it is not possible for all pupils to have access
to a microscope, it is fortunate that those who have
made physiology a careful study, and have examined
the various structures and tissues with great care,
have made drawings and sketches which we may
study. Thus we have here on the Aid a series of
marvelous paintings, true to nature, which we can
study with even more satisfaction than if we were to
prepare the specimens and look at them through the
microscope ourselves, We have spoken of the body

100 ELEMENTARY PHYSIOLOGY.

as "the house in which we live." We may carry the
comparison a little farther and consider the different
tissues as the material used in the body-building,
where they serve a purpose much like that of sand,
stone, lime, glass, bricks and so on, in the construc-
tion of a building.

MICROSCOPIC STRUCTURE.

Here (1) we see the three coats of the
(')". arteries. The outer layer is made
up of a fibrous matter, more or less
elastic. Next to it lies the middle coat, which
consists of alternating layers of elastic tissue and
muscular fibers, and the inner lining consists prin-
cipally of a net- work of elastic tissue.

As in the arteries, the veins under the
Vei^sf (*) microscope show three distinct coats,

but the entire vein wall is much thin-
ner than that of the artery. Here at (2) the structure
of the vein is shown. We see also the valves, men-
tioned under the circulation, which consists of pouch-
like folds of the inner coat. Here we see three
valves; but sometimes there are but two, and even
one. From their shape' and position you may see
that they will allow blood to pass through them in
one direction, but not in the other. Thus, blood can
not flow backward, which, you will perceive, is a very
wise provision. The shape of these valves as shown
here will suggest the appropriateness of the name,
semilunar valves.

LESSONS FROM THE MICROSCOPE. 101

of capiiia- At (3) we have represented the net-
ries between WOrk of capillaries which constitutes

Arteries

and veins (3). the connection between the arteries and
veins. Here the outer and middle walls of the
arteries have disappeared, and only the inner coat
remains. The filtering process can thus take place
with little difficulty.

of MUCOUS All cavities of the body which com-
Membrane (4.) municate directly or indirectly with
the outside surface are lined with a soft, smooth
membrane called the mucous membrane. This is a
continuation of the skin. At the lips, for example,
we may see that the skin merges into a softer and
more sensitive coat, the mucous membrane. Here,
at (4) you may notice its net- work of capillaries.
1.00 ed€a>ii- At (5) we see the capillary meshes of
lariesoftne the skin. Through their folds are

absorbed many substances which are
then carried into the system, as we learned under
Absorption. The activity of these capillaries as
absorbents makes it possible for sailors to quench
thirst by spraying their garments with sea water
when their supply of fresh water is exhausted. The
wet garments come in contact with the skin, and the
moisture is absorbed.

This (6) gives the eye an opportunity

tinai vim**) to aid tne min<l in comprehending the
outer structure of the villi. The vein
capillaries which take up the digested food are here
shown.

102 ELEMENTARY PHYSIOLOGY.

Number (7) gives us a view of the
thl JLunss^r). structure of the lungs. As you know,

the lungs are composed chiefly of cells
in which the imparities are exchanged for fresh
supplies of life-giving oxygen. Here these cells and
blood-capillaries are seen.

capillaries of •*• **e Par°tid, the principal one of the
the Parotid salivary glands, is also composed mostly

r (8), « .„ , , ,

Brain (9) and °* a capillary net-work, as shown here
cellular (g). At (9) we see the capillaries of

Tissue (1O).

the brain, with red and white corpuscles,
or blood-discs, passing through them, carrying
nourishment to the brain.

(10) shows how cells grow in length and then
split into .tissue-forming fibers. The cell, you will
remember, is the smallest possible part of the body,
and is the most important structure of the system,
since all tissues and organs are made up of cells, just
as sandstone is made up of millions of small grains
of sand. But sand is lifeless, while, in the living
body, life resides in the cell.

Under the microscope the muscular

Elastic Tis- «•',.., t

sues (ii),iius- fiber has the appearance as shown at
?S"™£* (12). It consists, of course, of many

(12), and Bone- ^ ' J

Corpuscles cells joined together, as will be seen
by carefully examining this cut. The
structure of the bones, with their canals and little
lakes, through which their nourishment is carried, is
nicely shown at (13). Examine it carefully, and
then procure, if possible, a bone cut crosswise, and
compare.

LESSONS FROM THE MICROSCOPE. 103

voluntary We ^ave seen that voluntary muscles
muscles (14). are made up of bundles of fibers. This
is beautifully shown here. We also see the cross-
markings, or strice, which is a peculiarity of volun-
tary muscles. An examination of a piece of cooked
beef will be helpful in connection with this view.

The all-important gastric juice, so much
needed in a proper digestion of the
food, is secreted by glands of the
stomach wall. Such a gland is here represented in
a very admirable manner. From the little mouths
here seen, exudes the gastric fluid during the pro-
cess of digestion.

At (16) and (17) are representations of

Xerve -fibers v '

of Brain (16), nerve-fibers of the brain. Their healthy
action, the abundance of their cells and

their proper nourishment largely determine our

mental capabilities.

The hepatic or liver vein, by which
lie- *^e blood is collected and carried from

paticvein(i8).the liver toward the heart, is here

shown as passing through the adjacent liver sub-

stance. The meshes of the liver capillaries are also

seen. In these the bile is secreted.

The microscopic appearance of the

Kidney , , * Ai i • i - i

structure (it>). structure or the kidneys is here repre-
sented (19). The peculiar little cap-
sules or balls, called Malpighian Corpuscles, are a
part of the mysterious organism provided for the
secretion of the urea from the blood.

104 ELEMENTARY PHYSIOLOGY.

Red Blood ^S' (20) shows the red corpuscles

of the blood of different animals.

Blood consists of a countless number
of solid bodies floating in a liquid. Some of these
solids are of a red color, while others are pale or
white. These solids are called corpuscles or blood-
discs. They vary also in shape in different ani-
mals. In man, the discs are usually nearly or quite
circular, though, when seen in different positions,
they present different appearances; 'just as a coin,
looked at perpendicularly to its surface, looks cir-
cular, and, when we look at it edgewise, seems of
an entirely* different shape. These wonderful little
bodies are so small that, of the red discs, 3,500, laid
side by side, would measure only an inch, and, if
placed one upon another, 18,000 would be required
to make a column of that height. They usually
arrange themselves in piles, and fit in each other
like so many saucers or butter plates. It is the
great number of these corpuscles which gives blood
its color.

The structure of the strong tendons by

niter pi™ which the muscles are attached to the
Adipose Tis- bones, is shown very plainly at (21,.
As will be seen here they consist of
many longitudinal fibers. Number (22) shows us
how adipose cells appear under the microscope
(23), and gives us another view of the structure of
the bones. This is from the ulna of the forearm.

LESSONS FROM THE MICROSCOPE. 105

The mucous membrane lining the
mouth, nose and other cavities com-
Ceiis of Kpi- municating with the outside, is covered

dermis

at (24) we have a magnified view of these cells from
the mouth; at (25) we see, as through a micro-
scope, the cells of the epidermis. Though the worn-
out particles of the cr.ticle can be seen with the
naked eye, their peculiar structure can not bo thus
perceived.

The choroid coat of the eye is of a

Pigment from

<;oat dark color, and absorbs the superflu-
(26). ous ^^ brought into the eye. Its

color is due to a dark pigment consisting of regu-
larly formed six-sided cells. Their shape is seen
at (26).

The bile is secreted in the liver cells,

Other Views • . * i« « •

to (3 1), a microscopic view of which is given

us at (28).

Each of the thirty-one pairs of spinal nerves has
two branches, as seen from (29). The posterior
root has a ganglion of nerve matter which has the
power of originating motion. (30 and (31) show
us how the different nerve-cells appear when seen
through the microscope.

Thus we have afforded us a series of views by a
careful study of which we may be led to appreciate
the fact that we are "fearfully and wonderfully
made."

EFFECTS OF ALCOHOL.

The principal organs of the body, and
8ound<Body *^e func^ons °^ each, are now quite

familiar to us. Let us now consider
briefly the necessity of guarding against anything
and everything which would in any way impair the
health of these organs, or interfere with them in the
performance of their work.

If a grain of sand should find its way into the
eye, inflammation would at once result; sight, the
function of the eye, would be interrupted. If, on
account of some disease, the muscles of the heart
should cease to contract and expand with their
ordinary regularity, or stop their action entirely,
the blood would cease to circulate and life would end.
Thus, the well-being of the body, yea, life itself,
depends upon the healthy action of the various
organs which are our servants in our body- house.

Does it not seem strange, then, that so
of the manv thousands should still persist in

abusing their bodies, which are made
"in the image of {heir Creator"? Yet there are
such who willfully take into their systems that
which not only interferes with the healthy action of
their bodily organs, but leads to certain death. More
than this, they injure not only their bodies, but
destroy their mental faculties, dethrone reason,
bring misery and woe upon their families, and fail
to accomplish life's ends.

EFFECTS OF ALCOHOL. 107

What is strong drink? It is a liquid
strong Drink. which contains ai^hol in large or small

quantity; and, if taken into the system, will affect,
more or less, all the organs and tissues of the body;
and, if the quantity is sufficient, will cause what is
called drunkenness or intoxication.

It is a liquid which in appearance can
what is if?* not be distinguished from water. If

one vial be filled with water and an-
other with alcohol, at a little distance it cannot be
told which contains the water and which the alcohol.
But the properties of the two are remarkably dif-
ferent. The alcohol has a strong odor, and a hot,
biting taste. A small quantity may be placed in a
shallow dish and a burning match held to it, when
it will readily burn with a pale flame, but giving
off much heat. If the white (albumen) of an egg
be put in a cup, and alcohol poured on it, the albu-
men will soon become white, hard and tough, as if
cooked. In all these and in many other particulars,
it differs very much from water, which it so much
resembles in appearance.

Nearly all of the grains, as wheat, rye,
origin?8 barley, corn and rice, contain much

starch. Corn-starch is made from corn,
and sold by the grocer. The starch of these grains
can, under certain circumstances, be converted into
sugar, and this, in turn, can be changed into two
very different substances, carbonic acid gas and

108 ELEMENTARY PHYSIOLOGY.

alcohol. Thus alcohol may be made from many sub
stances. The juices of all fruits contain the sugar
from which it may be produced. From the grape,
currant, blackberry, elderberry and cherry, wine
is made; from apples, cider is pressed; whisky is
made from corn, barley, rye and other grains; rum
is made from molasses and sugar cane. All of
these contain alcohol in different quantities.

If you take an apple and squeeze out

Sone?8 °^ ^ ^ie Ju^ce' y°u wiH have cider.

If this is allowed to stand in the
warm open air, it will very soon begin to change its
nature. If watched closely, small bubbles will be
seen rising to the top and escaping. These are bub-
bles of carbonic acid gas, one of the products of the
change of the fruit-sugar. The other is alcohol,
which mixes with the liquid. The cider is now no
longer sweet, but contains alcohol, is properly called
"hard cider," and is a dangerous drink. It is
the escaping gas that makes cider sparkle, and
beer foam.

The change of the cider, from sweet to
Fermentation-hard, or from the harmless juice of the
apple to that containing alcohol, is called fermenta-
tion. All alcohol is the result of the fermentation
of sugar, or some substance containing sugar. The
apple juice, as soon as exposed to the warm atmos-
phere, absorbs from the air a peculiar substance
called a ferment, which is something like yeast. It

EFFECTS OF ALCOHOL. 109

at once begins to " worK," that is, it begins to change
the sugar to carbonic acid gas and alcohol. Thus
wine is made from grapes, currants and other fruits.
This kind of fermentation is called vinous fermenta-
tion.

If the process of fermentation is allowed
Fermentation ^° continue, the hard cider and the fer-
mented wine will again change their
nature. If a barrel containing cider is left in
the warm sun, with an open bung (why), it first
changes its sugar into alcohol. Additional ferment
will change the alcohol of the hard cider to acetic
acid, or cider-vinegar. This is called acetous fer-
mentation.

Beer brewers add water to barley,
>m

IJarley.

and keep it sufficiently warm to cause

it to sprout, when the starch it contains
will change to sugar. More heat is added, and the
germs or young sprouts are killed, and the water
evaporated. This is now called malt, which is
soaked in water, the sugar which it contains is dis-
solved and the sweet liquid drained off. Yeast is
added to this liquid, to start the process of fermen-
tation, or change of sugar to carbonic acid gas and
alcohol. It is now called beer.

If a cold cup be inverted and held

Distillation.

over the spout of a tea-kettle from
which steam is escaping, the steam will be condensed
and gather in drops on the inner surface of the cup.

110 ELEMENT AE Y PHYSIOLOG Y.

The water is first changed to vapor and this in
turn is condensed to a liquid again. This is called
distillation.

Now, if a quantity of wine or hard cider be
placed in a vessel with an opening something like
the spout of a tea-kettle, and heat applied, distilla-
tion will take place. But alcohol will boil, that is,
change to vapor, at a temperature of 173°, while
water requires 212°. Hence, the alcohol will be
vaporized and pass off as steam before the watery
portions will have reached a sufficient temperature.
Thus, the vapor of alcohol can be condensed and
collected as almost or quite pure alcohol. But suffi-
cient heat may be applied to drive off some of the
water with the alcohol. When about as much water
is driven off as alcohol, the result of the process of
distillation is brandy, whisky or rum.

Thus, we have seen that there are

Two Classes

or strong two kinds, or classes, of strong drink,

the pernicious element in each being
alcohol. One kind is called fermented liquors, such
as wine, beer, ale and cider, and contain from three
to twenty per cent, of alcohol. The other kind is
known as distilled liquors, rum, whisky and brandy,
containing as high as fifty-five per cent, of alcohol.
An appetite for these liquors is the cause of more
poverty, unhappiness, wickedness and crime than all
other causes combined. We will now consider their
effects upon the human system,

EFFECTS OF ALCOHOL. Ill

EFFECTS ON THE DIGKESTIVE SYSTEM.

To possess a healthy digestion is a
great blessing. It is essential to our
physical well-being. Here we have a
fine representation of a healthy stomach and liver.
(See Aid.) The liver naturally lies across the
stomach, but here* it is turned up to show us the
healthy appearance of a stomach which has never
been abused by that terrible destroyer, alcohol.

If taken in an undiluted form, alcohol
" would burn the mouth and throat. The
stomach would suffer in a similar way. But in its
most diluted form it has an irritating effect upon
the lining membrane of the stomach and intestines.
Inflammation tells the story of the unnatural condi-
tion of things. The gastric juice becomes thick and
unfit for its work in the digestive process. The
constant inflammation indicates unnatural heat, and
an unnatural thirst ensues, which is the probable
reason for the fact that the more liquor a man drinks
the more he wants. The quantity he drinks to-day
will not satisfy him to-morrow, since more and more
will be needed to counteract the ever-increasing
inflammation.

This second cut shows us plainly the early stages
of inflammation. It represents, perhaps, the stomach
of one who has had his first experience with the
deadly stuff; and yet how different in appearance
from the stomach represented above.

OF THP

UNIVERSITY

112 ELEMENTARY PHYSIOLOGY.

At the bottom of this chart we see a
uiceration. more a(jvanced stage of the difficulty.
The blood-vessels are very much dilated, and indi-
cate that extraordinary work has devolved upon this
organ. The blood-vessels seem to have lost their
power to contract sufficiently to expel the increased
amount of blood brought hither. And here we see
the results (first cut, next chart), of long continued
distension of the blood-vessels. They have broken
and sores or ulcers are the result. The stomach is
now no longer able to perform its functions; the
food is no longer properly digested, and as a con-
sequence the blood is impoverished, and the general
health has failed. All on account of the drink-habit
which has now become so firmly fixed upon its victim
that it is almost beyond human effort to break loose
from it.

The faithful servant of the body, the

L,ast Stages * '

of Alcohol stomach, tries, from the first, to adapt
ins" itself to the derangements caused by
the use of alcohol as a beverage. Just as the cuti-
cle of the hand thickens and hardens, when we use
an ax or shovel, so the stomach, if it is constantly
being irritated by the presence of alcohol, becomes
thick, tough and unnatural; and consequently
becomes better adapted for the purpose of a whisky
jug, but less for the purpose for which it was
intended to digest food. The blood vessels of the
stomach, having been dilated to their utmost, their
diseased walls give way and ugly ulcers are formed.

THE EFFECTS OF ALCOHOL. 113

These canker-like eruptions seen here, first eat
through the inner coat, then the outer is attacked
and the painful sores cause great suffering. Ulti-
mately it can no longer accommodate itself to the
condition of things. It gives up in despair. It can
no longer retain and much less digest food. Its con-
dition and appearance is shown here on the chart.
A long and painful disease follows, and at last death
relieves the poor slave to appetite.

Let us observe right here, how gradual is the pro-
cess. How small and seemingly insignificant the
beginning. And yet how certainly does the gratifi-
cation of one thirst create the next. We would all do
well to accept as our motto: " Touch not, taste not,
handle not."

We have just seen how alarming is the
effect of alcohol on the stomach. But
the liver, the healthy action of which
we have found so necessary in the food-preparing
and blood-purifying processes, suffers fully as much
from the use of alcoholic drinks.

It is probable that most of the alcohol taken into
the stomach is there absorbed and carried directly
to the liver without passing into the intestines. A
proper secretion of the bile in the liver demands that
the cellular structure of that organ remain un-
changed. Alcohol causes a change of these cells to
fatty tissue, and an enlargement of the organ follows.
Its tissues then become lumpy or knobbed, and pro-
duces what is known as u gin, or hobnailed liver."

114 ELEMENTARY PHYSIOLOGY.

Let us compare its appearance under such conditions
as we have it here represented, with its looks when
in health, as seen on a previous plate.

What is the result of a liver thus dis-
eased? The answer is two-fold: First,
the bile and liver sugar are not properly taken from
the blood, and whatever poisonous matter may be
contained in the blood which should be removed
with the bile must remain in the system, and will
certainly prove destructive to health. In the second
place, the digestive process is not furnished with
the needed bile, and the work of preparing the food
will be imperfectly performed.

The effect of a continued use of alcohol
fhe°Kidnry8. uPon the kidneys is much like that
upon the liver. In the kidneys the
blood is constantly being filtered, and the poisonous
urea is being taken from it and expelled from the
body. If the blood carries alcohol into the cells of
these organs they will be irritated, inflamed, and
sometimes destroyed. This is known as Brighfs
disease, though other causes may lead to the same
difficulties and terminate in the same disease. Here
we have a view of a very common derangement with
drinkers. It is an accumulation of fat about the
kidneys, and may prove fatal.

EFFECTS ON THE NERVOUS SYSTEM.

Medical authorities tell us that after

On the Brain. ^ death Qf ft hard drinkerj more a]co_

hol is found in the tissues of the various parts of

THE EFFECTS OF ALCOHOL. 115

the nervous system than any other part of the body.
It has been found in sufficient quantities in the brain
to distill it from the brain tissue. Its abundance in
the nervous tissue is probably due to the amount of
water which nerve tissue contains, and for which
alcohol has a remarkable affinity or greed. As stated
elsewhere, if alcohol is poured in a cup contain-
ing the white of an egg , it will harden or coagulate
it. The tissue of the brain is similarly affected and
made less sensitive. This loss of feeling is called
paralysis. It also causes inflammation as seen here
in the first plate of this chart. Compare the appear-
ance of the two hemispheres of this important
organ, one side represents the brain in health and
the other as affected by strong drink.

THE BRAIN IS THE SEAT OF THE MIND.

If alcohol effects its tissues as we have
«><Liieii<-eK. iearne(j in the preceding topic, we may

understand to some extent at least, how the habitual
use of alcoholic drinks causes temporary insanity;
and men are made silly in their actions, boastful in
conversation and unmanly in every respect. That
part of the brain which controls the voluntary mus-
cles shows the effects of stimulants very promptly.
The hand trembles and shakes "like a leaf." Walk-
ing soon becomes a difficult task. The control of
the lips is lost and a quivering is the result. The
tongue becomes ungovernable, and the poor toper
becomes an object of pity, as he staggers through

116 ELEMENTARY PHYSIOLOGY.

the streets no longer a man, but a poor, degraded
wretch, made so by his appetite for drink.

The effect of alcohol upon the brain
sometimes manifests inself in a degen-

the Brain. eration of the brain tisssue. Fat accu-
mulates as a result of frequent intoxications and
the result is known as alcoholic softening, and the
appearance of the brain in such condition is showp
by the plate.

The last cut of the stomach on the tem-
Tremens! perance charts gave us a view of that
organ of a patient suffering from de-
lirium tremens. The Aid furnishes us a correspond-
ing view of the brain of such a patient. It is usually
supposed that this condition is reached only after
years of dissipation and drunkenness. Ordinarily this
is true. But reliable medical authorities affirm that
persons of a particularly nervous disposition are
sometimes attacked by this terrible malady when but
small quantities of intoxicants are taken. Those
who indulge in strong drink are never absolutely
safe. It may attack them at any time.

The victim of delirium tremens is in terrible fear
and anxiety. His mind is so completely disturbed
and his imagination so thoroughly aroused as to
cause him to think his best friends enemies who
would do him harm. He sees horrible sights and
hears noises which alarm him. In his awful con-
dition he raves and tears, cutting, tearing and biting
himself like a madman ; and not unfrequently dies

THE EFFECTS OF ALCOHOL. 117

and thus escapes from his agony. Oh, that human
beings should so abuse themselves as to bring them-
selves into such a condition !

The same paralyzing effect of alcohol
x^rve™* on the brain of which we made mention

in the preceding topics, is noticeable
in the nerves. The alcohol takes up the moisture
in the nerve tissues, leaving them more or less inca-
pable of transmitting sensation. There is on record
an account of a man, who, in his drunken stupor,
burned his foot almost to a crisp without becoming
conscious enough to remove it from the camp fire
into which he had unconsciously placed it. The
nerves were so thoroughly paralyzed by alcohol as
to fail to transmit sensation to the brain, even if
that organ had been in a fit condition to receive the
intelligence. The brain and nerve tissues are
among the first substances of the body to become
affected by alcohol.

The effect of alcohol on the heart is

more or less indirect- ft is through

it-ant* upon the affected nerves that its effect upon
the heart and circulation is brought
about. The action of the heart is governed by the
nerves, which act as a sort of brake, thus preventing
a too violent action. Now when these nerves be-
come affected and lose their control of the heart's
action, it will beat more rapidly, and also with
greater force. Thus the strain upon the heart is
greatly increased, while the intervals of rest be-

118 ELEMENTARY PHYSIOLOGY.

tween the beats is diminished, which must be injuri-
ous to that important organ. With the increased
activity of the heart, comes an increased rapidity
of the flow of blood through the blood-vessels-
The blood is forced to the surface, which becomes
flushed, and, if long continued, the blood-capillaries
at the surface lose their power of contraction, and
the drunkard's nose is the result.

As in the kidneys, the tissue of the heart-walls
will degenerate and change to fat. A fatty coat
may run back from about it, and it is known as fatty
accumulation. If the use of alcohol is continued,
the heart will finally succumb; its fibers will become
relaxed, its cavities become enlarged, it will entirely
lose its power to contract, and death will ensue from
paralysis of the heart

Sometimes the heart continues its efforts to expel
the blood, even when the cavities have increased
their capacity, and the walls become thin and weak.
Alcoholic rupture is then likely to occur. The effect
on the appearance of the nerves, eye and blood-
vessels is shown on the Aid.

"Without going farther into the details
synopsis. o£ a]cohol5 and other effects upon the
human system just mentioned in these lessons, let
us recall briefly what it will not do, and then resolve
never to use it except as a medicine, and then only
when directed to do so by a competent physician.
Following are a few of the many facts concerning
alcohol, which have so frequently been demonstrated

THE EFFECTS OF ALCOHOL. 119

as to be no longer questioned:

WHAT IT WILL NOT DO.

1. Alcohol is not a food, hence —

2. It will not nourish the system.

3. It is not assimilated and made a part of the
body tissue.

4. It will not fortify against cold.

5. It will not quench thirst.

6. It will not increase our powers of endurance.

7. It will not make the nerves more steady.

8. Its use will not make us more manly.

9. It will not increase our mental powers.

10. It will in no way benefit the system, except
as a prescribed medicine.

11. It will not prolong life.

12. Its use can in no way add to our good name
or reputation.

TOBACCO AND ITS EFFECTS.

The use of tobacco is so prevalent that all know
what it is. Like alcohol, it does little or nothing for
which its use can be recommended, while, on the
other hand, there are many reasons for which its use
should be entirely avoided.

It contains a substance called nicotine,

poLao°n0 IS * which is a deadl7 poison. This poison

can be extracted from the leaves of the

tobacco plant, and is a dark-colored liquid of a

sharp, biting taste. It has been found that a few

120 ELEMENTARY PHYSIOLOGY.

drops of this poison, placed on the tongue of a dog,
will cause death. This nicotine, extracted from the
tobacco and evaporated, forms large parts of the
crust in the bowl of an old tobacco pipe.

Its use is unnatural. When first at-
<mtheireCt8 tempted, it causes nausea and nervous
Young:. and muscular weakness. It is a well-

known fact that it exerts a very perni-
cious influence, particularly upon the young. It
prevents their physical and mental development; it
stunts their growth, and paves the way for disease
in after years.

Injurious as tobacco smoking (in its
common form) may be, smoking cigar-
ettes is even more so. The poorest
kind of tobacco is often used in making them, and
poisonous substances are added to give them the
proper strength and flavor. Opium, which is used
in considerable quantities in this adulteration, is
carried with the smoke to the lungs. Nicotine, that
deadly poison found in tobacco, aids in the poison-
ing process. In view of the detrimental effect of
cigarettes, it is not surprising that a number of
States have enacted laws prohibiting the sale of
cigarettes to young boys.

To show you that 'the mucous lining of
ment.X1 *^e mouth and air passages is sub-

jected to a sort of tanning process, and
thus has its ordinary functions impaired by cigar-
ette smoking, a simple experiment may be per-

TOBACCO AND ITS EFFECTS.

formed. If we take a clean white cloth or handker-
chief, two or three double, and inhale the smoke of
a lighted cigarette, and then force it from the mouth
through the cloth, a brownish yellow spot or stain
will be found on it, which consists of the poisonous
nicotine and other ingredients contained in the
smoke, and mixed with the moisture of the mouth.
Deposits of this kind are made upon the walls of the
air passages when cigarettes are smoked, which
must be injurious.

The respiratory organs suffer the most
The Respira- from cigarette smoking. We have here

tory Organs.

HOW Affected. (See Aid.) a series of views which will
help us to understand the nature of the
harm done, and, by a careful study of these, we may,
perhaps, all be led to the resolve never to smoke
cigarettes or cigars.

The trachea, or wind-pipe, in health has the
appearance shown at 1 and 2; 4 shows us how
it looks inside, and 3 outside, when it has become
inflamed and irritated by the use of cigarettes. The
inner structure of the lungs, with its subdivisions
of the bronchial tubes and air-cells, in health, is
nicely represented at 5. Here also we see the
plump, full, well-formed lung before it has become
shriveled up by the contents of the cigarette smoke.
At 6 we see the effects. The air cells are filled
up, and the bronchial subdivisions are almost
wholly obstructed by nicotine deposits.

How, then, can the blood -purify ing process be

122 ELEMENTARY PHYSIOLOGY.

successfully carried on in such a lung as is here
represented ?

Here in the lower right-hand corner of this plate
we have a view of what is left of the lung after years
of cigarette smoking. Nicotine has filled every air-
cell. Nicotine had caused his death.

In the opposite lower corner on the Aid is seen
a view of what is called smoker's cancer. It usually
occurs in the throat and often proves fatal.

We have now briefly considered the
essential features in the structure of
the human body and the principal functions of the
various organs. What is beneficial, as well as what
is harmful, in its effects, has received attention.
With the assistance of the Anatomical Aid, we have
endeavored to impress the mind with some of the
effects of alcohol and tobacco. If now, by the use
of this little book in connection with the Aid, our
young people may be induced to study the wonder-
ful mechanism of their bodies, and try to avoid that
which is injurious or in any way interferes with
their physical or mental well-being, we shall have
accomplished our purpose.

APPENDIX.

INDEX

TO THE

COMPLETE NERVOUS SYSTEM.

I. THE CKANIAL AND SPINAL SYSTEM.

No. Common Name.

1 Brain.

2 Small Brain.

3 Tree of Life.

4 Yard's Bridge.

5 Three fold Nerve.

6 Abducent Nerve.

7 Face and Sound Nerve.

8 Tongue and Pharynx Nerve.

9 Willis' Accessory Nerve.

10 Loose cavity containing lung

and stomach nerve ducts.

11 Lower tongue nerve.

12 Descending branches hypo-

glossal nerves.

13 Cranial portion of the Spinal

Cord.

14 Decussate pyramid.

15 Part of cervical spinal cord.

Latin or Professional Name.
Cerebrum.
Cerebellum.
Arbor vitaB.
Pons Varolii.
Nervus Trigeminas.
Nervus abducens.
Nervus facialis et acousti-

cus.
Nervus glosso-pharyngeus,

vagus et accessorius.
Nervus accessorius Willisii.
Nervus vagus pneumo-gas-

tricus.

Nervus hypoglossus.
Kami descendens nervi hypo-

glossi.
Medulla oblongata.

Decussatio pyramidum.
Pars cervicalis medullas spi-
nalis.

11

APPENDIX.

No. Common Name.

16 Part of thoracic spinal cord.

17 Bulbous expansion at

end of spinal cord.

18 Terminal threads, spinal

cord.

19 Neck nerves 1.

20 Neck nerves 8.

21 Network of neck nerves.

22 Network of arm nerves.

23 Back bone nerve 1.

24 Back bone nerve 2.

25 Nerves between ribs.

26 Loin nerve 1.

27 Loin nerve 5.

28 Network of loin nerves.

29 Anterior crural nerve.

30 Hip — abdominal nerve.

Jl Hip — groin nerve.

32 Groin skin nerve.

33 Obturator nerve.

34 Sacral nerve 1.

35 Sacral nerve 5.

36 Network of sacral nerves.

37 Coccyx nerves.

38 Sympathetic nerve.

39 Upper cervical ganglion.

40 Middle cervical ganglion.

41 Lower cervical ganglion.

42 Thoracic ganglia.

43 Loin ganglia.

44 Sacral ganglia.

45 Coccyx ganglion.

46 Connecting branches be-

tween sacral and sympa-
thetic nerves.

Latin or Professional Name.
Pars thoracica medullae spi.
nails.

Filum terminals.

Nervus cervicalis 1.

Nervus cervicalis 8.

Plexus cervicalis.

Plexus brachialis.

Nervus dorsalis 1.

Nervus dorsalis 2.

Nervi intercostales.

Nervus lumbalis 1.

Nervus lumbalis 5.

Plexus lumbalis.

Nervus cruralis anterior.

Nervus ilio — hypogas tri-
cus (ramus exterior et in-
terior).

Nervus ilio inguinalis.

Nervus inguino cutaneous.

Nervus obturatorius.

Nervus sacralis 1.

Nervus sacralis 5.

Plexus sacralis.

Nervi coccygei.

Nervus sympaticus.

Ganglion cervicale superior.

Ganglion cervicala medium.

Ganglion cervicale inferior.

Ganglia thoracica.

Ganglia lumbalia.

Ganglia sacralia.

Ganglion coccygeum.

NERVOUS SYSTEM.

iii

No. Common Name.

47 Sciatic nerve (Hip nerve).

48 Groin nerve.

49 Shoulder bone nerves.

50 Branches of skin and axle

nerves.

51 Arm skin nerves, internal

posterior.

52 Arm skin nerve, small in-

ternal.

53 Branches middle skin nerves

(arm).

54 Middle arm skin nerve.

55 Branches skin palm nerves of

middle skin nerve.

56 Branches of middle under

skin nerve over ulna.

57 Branches under skin nerves,

overlying cutaneous mus-
cle.

58 Radial nerve branches.

59 Voluntary ulna nerve.

60 Voluntary fioger nerves.

61 Network of arm pit nerves.

62 Middle nerve, sending

branches to thumb, index
and middle finger and
radial side of ring ringer.

63 Ulna nerve.

64 Voluntary ulna nerve,

65 Spiral muscular nerve lying

against radius.

66 External elbow joint nerve.

67 Superficial radial nerve.

68 Musculo cutaneus nerve.

69 Anterior leg nerve.

70 External anterior femoral

nerve.

Latin or Professional Name.
Nervus ischiadicus.
Nervus inguinalis.
Nervi supraclaviculares.
Kami cutaneus et nervi ax-

illaris.
Nervi cutaue us brachii, in-

ternus posterior.
Nervi cutaneus brachii inter-

nus (minor).
Bamus nervi cutanei medii.

Nervue cutaneus brachii

medius v. internus major.
Kamus cutaneus palmaris,

nerv. cutan. medii.
Ramus outaneus ulnaris

nerv. cutan. medii.
Ramus cutaneous nerv. raus-

culo cutanei.

Ramus nervi radiales.
Nervus ulnaris volaris.
Nervus digitales volaris.
Plexus axillaris (brachialis).
Nervus medianus.

Nervus ulnaris.
Nervus ulnaris volaris.
Nervus musculo — spiralus v.

radialis.

Nervus interosseus externus.
Nervus radialis superficialis.
Nervus musculo— cutaneus.
Nervus cruralis anterior.
Nervus cutaneus femoris

anterior externa.

iv

APPENDIX.

No. Common Name.

71 Groin nerve.

72 Groin skin nerve.

73 Large saphenic nerve.

74 Middle anterior femoral

nerve.

75 Internal anterior femoral

nerve lying against small
saphenic.

76 Branches of hip abdominal

nerves.

77 Branches hip groin nerves.

78 Branches muscular leg

nerves.

79 Superficial peroneal nerve

fibular.

80 Internal foot skin nerve.

81 Middle foot skin nerve.

82 External leg skin nerve.

83 Deep peroneal or fibular

nerve.

84 Deep branch of peroneal

nerve.

85 External branch of peroneal

nerve.

86 Cervical or neck back bone

joint.

87 Back bone joint (1).

88 Back bone joint (12).

89 Loin back bone joint (1).

90 Loin back bone joint (2).

91 Sacrum bone.

92 Coccyx bone.

93 First rib.

94 Last rib.

95 Crest of ilium bone.

Latin or Professional Name.

Nervus inguinalis.

Nervus inguino cutaneus.

Nervus saphenus major.

Nervus cutaneus femoris
anterior mediue.

Nervus cutaneus femoris
anterior internus v. saphe-
nus minor.

Rami nervi ilio hipogastrici.

Kami nervi ilio inguinalis.
Eami musculares nervi cru-

ralis.
Nervus peronaeus superfi-

cialis, con.
Nervus cutaneus dorsi pedis

internus, et.
Nervus cutaneus dorsi pedis

medius.
Nervus cutaneus c r u r i s

externus.
Nervus perouaeus profundus.

Eamus internus peronaeus

profundus.
Bamus externus peronseus

profundus.
Vertebra cervici (7).

Vertebra dorsi (1).
Vertebra dorsi (12).
Vertebra lumbalis (1).
Vertebra lumbalis (2).
Os sacrum.
Os coccygi.
Costa prima.
Costa termina.
Crista osais ilii.

NERVOUS SYSTEM.

No. Common Name. Latin or Professional Name.

96 Underlying collar muscle Musculus sterno — cleido

connecting with dternum. mastoidens.

97 Front scalene muscle. Musculus scalenus anticus.

98 Middle scalene muscle. Musculus scalenus medins.

99 Internal intercostal muscles. Musculi intercostales inter-

100 External intercostal mus-

cles.

101 Square loin muscle.

102 Large loin muscle.

1 03 Internal iliacal muscle.

104 Deltoid muscle (shoulder).

105 Large breast muscle.

106 Flexible forearm muscle.

107 Fold in forearm.
10« Head of ulna.

109 Aponeuroses of the palm.

110 Fleshy ball of thumb.

111 Short palm muscle.

112 Cephalic vein (arm).

113 Basilical vein.

114 Middle basilical vein.

115 Middle cephalic vein.

116 Head of humeris bone.

117 Sharp process of scapula.

118 Deltoid muscle.

119 See No. 105.

120 Small breast muscle.

121 Flexible muscle of biceps.-

122 Short head of biceps muscl e.

123 Long head of biceps muscle.

124 Coracoid arm muscle.

125 Internal arm muscle.

ni.

Musculi intercostales exter-

ni.
Musculus quadratus lumbo-

rum.

Musculus psoas major.
Musculus iliacus internus.
Musculus deltoideus.
Musculus pectoralis major.
Musculus biceps flexon cub-

iti.

Plica cubiti.
Caput ulnae.
Aponeurosis palmaris.

Musculus palmaris brevis.
Vena cephalica brachii.
Vena basilica.
Vena median a basilica.
Vena mediana cephalica.
Caput ossis humeri.
Processus coracoideus.
Musculus deltoideus.

Musculus pectoralis minor.

Musculus biceps flexor cub-
iti.

Caput breve, musculus bici-
pitis.

Caput longum, musculus bi-
cipitis.

Musculus coraco-brachialis.

Musculus interna brachialis.

VI

APPENDIX.

No. Common Name.

126 Internal head of extending

triceps muscle.

127 Long head of extending tri-

ceps muscle.

128 Muscle, serving to turn

palm of hand upwards.

129 Muscle, long, round extend-

ing wrist.

130 Muscle, serving to turn

palm of hand downward.

131 Round wrist muscle bend-

ing or turning.

132 Short, like functions as 128.

133 Common bending finger

muscles.

134 One of the wrist bending

muscles.

135 Long bending striking mus-

cle.

136 Muscles serving thumb.

137 Drawing thumb to the in-

dex finger.

138 Shoulder artery.

139 Arm arteries and veins.

Arteries and veins of uJna.

142 Upper anterior spine of

ilium.

143 Tailor's muscle.

144 Middle gluteal muscle (serv-

ing to turn thigh in and
outward).

145 Deep leg stretching muscle.

146 Straight femoral muscle.

147 External vastus muscle.

148 Muscle, serving to bring

thigh together.

Latin or Professional Name.
Caput internum, m. tricipitis

extensoris.
Caput longum m. tricipitis

extensoris.
Musculus supinator longus.

Musculus extensor carpi

radialis longus.
Musculus pronator teres.

Musculus flexor carpi radia-
lis.

Musculus supinator brevis.

Musculi flexores, digitorum
communes.

Musculus flexor carpi ulna-
ris.

Musculus flexor pollicis
longus.

Musculus abductor et flexor
brevis pollicis.

Musculus abductor pollicis.

Arteria axillaris.

Arteriae et venae brachialis.

Arteriae et venae ulnaris.
Spina ilii anterior superior.

Musculus sartorius.
Musculus glutaaus medius.

Musculus tensor faciae latae.
Musculus rectus femoris.
Musculus vastus externus.
Musculus pectinaeus.

NERVOUS SYSTEM.

Vll

No. Common Name.

149 Long drawing muscle.

150 Large drawing muscle.

151 Leg muscle.

152 Internal vastus muscle.

153 Tendon extending leg.

154 Knee.

155 Shin.

156 Internal ) Ankle joint pro-

157 External J ject,ions.
15? Transverse ligament.

159 Foremost tibial muscle.

160 Muscle, extending toes and

foot.

161 Long peroneal muscle (Fib-

ula).

162 Short peroneal muscle.

163 Long extending striking

foot muscle.

164 Counteracting on 160.

165 Short striking foot muscle.

166 Sole muscle.

167 Femoral artery.

168 Femoral vein.

169 Large saphenic vein.

Latin or Professional Name.
Musculus abductor longus.
Musculus abductor magnus.
Musculus cruralis.
Musculus vastus internus.
Tendo extensorius cruris.
Patella.
Tibia.

Malleolus internus.
Malleolus externus.
Ligamentum transversum.
Musculus tibialis anticus.
Musculus extensor digitor-

um pedis longus.
Musculus peronseus longus.

Musculus peronaeus brevis.
Musculus extensor pollicis

pedis longus.
Musculus extensor digitor-

um pedis brevis.
Musculus extensor pollicis

pedis brevis.
Musculus soleus.
Arteria femoralis.
Vena femoralis.
Vena saphena magna.

II. THE SYMPATHETIC SYSTEM.

DISTRIBUTION OF FACIAL AND PNETJMOQASTRIO
NERVES.

1 Descending thoracic aorta. Aorta descendens thoracica.

2 Innominate artery. Arteria innominata.

3 Bight under-shoulder artery. Arteria eubclavia dextra.

Vlll

APPENDIX.

No. Common Name.

4 Right carotid artery.

5 Internal carotid artery.

6 External carotid artery.

7 Upper thyroid artery.

8 External jaw artery.

9 Occipital artery.

10 Upper ear artery.

11 Temporal artery.

12 Pulmonary arteries and

veins.

13 Intercostal arteries and veins.

14 Descending aorta (abdom-

inal) with lower aortic
plexus.

15 Cceliac artery and plexus.

16 Kidney artery and plexus.

17 Upper mesenteric artery

with plexus.

18 Lower mesenteric artery

with plexus.

19 Common iliacal artery.

20 Network of upper abdominal

nerves.

21 Network of hsemorrhoidal

nerves.

22 Network of nerves surround-

ing bladder.

23 Network of prostate nerves.

24 Network of lower abdominal

nerves.

25 Lower phrenic arteries with

network of phrenic nerves.

Latin or Professional Name.
Arteria carotis communis

dextra.

Arteria carotis interna.
Arteria carotis externa.
. Arteria thyroidea sup.
Arteria rnaxillaris externa (v.

facialis).

Arteria occipitalis.
Arteria auricularis superior.
Arteria temporalis.
Arteriseet venae pulmonales.

Arterise et vense intercostal is
Aorta descendens abdom-

inalis, con plexus aorticus

inferior.
Arteria coeliaca con plexus

creliacus.
Arteria renalis con plexus

renalis.
Arteria mesenterica superior

con plexust mesentericus

sup.
Arteria mesenterica inferior

con plexus mesentericus

inferior.

Arteria iliaca communis.
Plexus hypogastricus su-
perior.
Plexus haemorrhoidales.

Plexus vesicalis.

Plexus prostaticus.

Plexus hypogastricus in-
ferior.

Arterise phrenicse inferiores
con plexus phrenicus.

NERVOUS SYSTEM.

IX

No. Common Name.

26 Great network of stomach

nerves.

27 Splenic artery with network

of splenic nerves.

28 Liver artery with network of

liver nerves.

29 Upper network with semi-

lunar ganglion.

30 Loin ganglion.

31 Sacral ganglion.

32 Thoracic gland 1.

33 Thoracic gland 7.

34 Large splanchnic nerve.

35 Small splanchnic nerve.

36 Upper network of thoracic

nerves.

37 Lower ganglion of neck

nerves.

38 Middle ganglion of neck

nerves.

39 Upper ganglion of neck

nerves.

40 Network of nerve molles.

41 Front ear nerve.

42 Posterior ear nerve.

43 Facial nerves and branches

causing goose flesh on skin.

44 Small occipital and upper

ear nerve.

45 Willis' accessory nerve.

46 Network of neck nerves.

47 Vagus nerve.

48 Recurrent nerve.

49 Phrenic nerve.

50 Network of arm nerves.

51 Network of loin nerves.

52 Network of sacral nerves.

Latin or Professional Name.
Plexus gastricus magnus.

Arteria splenica con plexus

splenicus.
Arteria hepatica con plexus

hepaticus.
Plexus Solaris con ganglion

semi-lunarius.
Ganglion lum bale.
Ganglion sacrale.
Ganglion thoracicum 1.
Ganglion thoracicum 7.
Nervus splanchnicus major.
Nervus splanchnicus minor.
Plexus thoracicus superior.

Ganglion cervicale inferior.
Ganglion cervicale medina.
Ganglion cervicale superior.

Plexus nervorum mollium.

Nervus auricularis anterior.

Nervus auricularis posterior.

Nervus facialis et pes an-
serius.

Nervus occipitalis minor ei
nervus auricularis supe-
rior.

Nervus accessorius Willisii.

Plexus cervicales.

Nervus vagus.

Nervus recurrens.

Nervus phrenicue.

Plexus brachialis.

Plexus lumbalis.

Plexus sacralis.

APPENDIX.

No. Common Name.

53 Nerves between ribs (inter-

costal.

54 Network of nerves of the

gullet (cesophagus.)

55 Network of nerves of lungs.

56 Network of nerves of phar-

ynx.

57 Lower jawbone.

58 Hyoid bone.

59 Shoulder bone or clavicle.

60 First rib.

61 Second rib.

62 Eleventh rib.

63 Transverse process of the

loin backbone.

64 Sacrum bone.

65 Pubis bone

66 Large cheek muscle.

67 Lower digastric jaw muscle.

68 Chewing muscle.

69 Salivary or parotid gland.

70 Under jaw gland.

71 Sterno-hyoid muscle.

72 Foremost scalene muscle.

73 Middle and posterior scal-

ene muscle.

74 Midriff.

75 Square loin muscle.

76 Eight bronchus.

77 Kidney.

78 Upper kidney gland.

79 6ullet.

80 Stomach.

8 1 Je j un um in testine.

82 Colon intestine.

Latin or Professional Name.
Nervi intercostalis.

Plexus oesophagens.

Plexus pulmonalie.
Plexus pharyngens.

Os maxillare inferius.

Os hyoides.

Clavicula.

Costa I.

Costa II.

Costa XT.

Processus transversus verte-
brae lumbalis.
Os sacrum.
Os pubis (symphysis).
Musculus zygomanticus

major.

Musculus digaetricus maxil-
lae inferioris.
Musculus masseter.
Glandula parotis.
Glandula sub maxillaris.
Musculus sterno-hyoidens.
Musculus scalenus anticus.
Musculus scalenus medius

et posticus.
Diaphragm.
Musculus quadratus lum-

borum.

Bronchus dexter.
Renes.

Glandula supra renalie.
(Esophagus.
Stomachus.
Intestinum jejunum.
Inteetinutn colon.

NERVOUS SYSTEM.

XI

No. Common Name.

83 Rectum intestine.

81 Bladder.

8-") Ureter.

80 Procumbent gland.

S7 Carrying vessel.

83 Spermatic cord.

89 Internal spermatic arteries
and veins with network
of internal spermatic
nerves.

Latin or Professional Name.

Intestmum rectum.

Vesica urinaria.

Ureter.

Gland ul a prostratus.

Vas deferens.

Chorda spermatica.

Arteria et vena spermatica
con plexus spermaticus in-
tern us.

III. THE SENSE OF SMELL.

VERTICAL SECTION OF NASAL, CAVITY.

1 Cavity in frontal bone.

2 Nasal bone.

3 Sphenoidal cavity.

4 Cribiform plate of the eth-

moidal bone.

5 Upper jawbone.

6 Incisive canal.

7 Hard palate.

8 Palate molles against soft

palate.

9 Tongue.

10 Nasal partition.

11 Posterior nasal cavity.

12 Roof of mouth.

13 Tonsils.

14 Pharyngeal palate arch.

15 Olfactory nerve.

16 Nasal-palate nerve of soarpa.

17 Incisive ganglion.

Sinus frontalis ossie frontis.
Os nasi.

Sinus sphenoidalis.
Lamina cribrosa ossis eth-

moidea.

Os maxillare superioris.
Canalis incivious.
Palatum durum.
Palatum molle v. velum

palatinum.
Lingua.
Septum nasi.
Posterior nares.
Pharynx.
Tonsilla.

Arcus pharyngo — palatinus.
Nervus olfactorius.
Nervus naso-palatinus scar-

pse.
Ganglion incisivum.

ill

APPENDIX.

IV. THE SENSE OF TASTE.

NERVES OF PALATE AND TONGUE.

No. Common Name.

1 Taste nerves.

2 Tongue and pharynx nerve.

3 Branches of three-fold taste

nerve.

4 Branches of No. 2.

5 Upper lip.

6 Hard palate.

7 Soft palate.

8 Uvula.

9 Side nerve of tongue.

10 Arch of pharynx.

11 Tonsil.

12 Entrance to gullet.

13 Root cf tongue.

14 Tongue.

Latin or Professional Name.
Nervi palatini.
Nervus glosso-pharyngeus.
Ramus gustatorius nervi

trigemini.
Ramus nervi glosso-phar-

yngei (pro. m. glosso-pala-

tino).

Labium superioris.
Palatum durum.
Velum palatinum v. palatum

raolle.
Uvula.

Arcus glosso-palatinus.
Arcus pharyngo-palatinue.
Tonsilla.

Isthmus faucium.
Radix lingua.
Lingua.

V. THE SENSE OF SIGHT.

VERTICAL SECTION OF ORBIT AND GLOBE OF EYE.

1 Frontal bone.

2 Upper jawbone.

3 Fatty matter.

4 Frontal muscle.

5 Upper eyelid.

6 Lower eyelid.

7 Lower oblique eye muscle.

8 Rectal eye muscle, lower.

Os frontis.

Os maxillare superius.

Adipose tissue.

Musculus frontalis.

Palpebra superior.

Palpebra inferior.

Musculus obliquus oculi
inferior.

Musculus rectus oculi in-
ferior.

NERVOUS SYSTEM.

Xlll

No. Common Name.

9 Rectal eye muscle, external.

10 Rectal eye muscle, upper.

11 Upper eyelid muscle.

12
13
14

15

16
17

18
19
20
21
22
23
24
25
26
27

Latin or Professional Name.

Musculus rectus oculi, ex-
ternus.

Musculus rectus oculi su-
perior.

Musculus levator palpebrae
superior.

Nervus opticus.

CDnjunctiva palpebrae.

Eye nerve.

Conjunction of Eyelids.

Reflection of conjunction from inner surface of eyelids to

globe.
Conjunction of eyelids and Conjunctiva scleroticse (bul-

white of eye. bi.)

Conjunction of 'cornea. Conjunctiva cornea.

Strong horny membrane Cornea.

forming outer part of eye.
Membrane of aqueous humor, lining anterior chamber.

Anterior camera.

Posterior camera.

Sinus of iris.

Sclerotic tunic.

Crystalline lens.

Ciliary body.

Vitreous body, glassy matter.

Tunic of the retina.

Tunic of the choroid.

Camera oculi anterior.
Camera oculi posterior.
Sinus venosis iridis.
Tunica sclerotica,
Lens crystallina.
Corpus ciliare.
Corpus vitreum.
Tunica retina.
Tunica choroidea.

VI. THE SENSE OF HEAKING.

THE INTERNAL ORGANS OF HEARING EXPOSED
WITHOUT BONY STRUCTURES.

1 "External ear.

2 Auditory canal.

3 Tympanum.

4 Hammer.

5 Handle of same, long.

Auricula extern a.

Meatus auditor, externus.

Membrana tympani.

Malleus.

Processus longus mallei.

XIV

APPENDIX.

No. Common Name.

6 Mannubrium of hammer.

7 Anvil.

8 Short process of same.

9 Long process of same.

10 Orbicular ossicle.

11 Stapes.

12 Vestibule.

13 Upper semicircular canal.

14 Posterior semicircular canal.

15 Lower semicircular canal.

16 Shell, spiral cavity.

17 Cupok of shell.

Latin or Professional Name.

Mannubrium mallei.

Incus.

Processus brevis incudis.

Proceesus longus incudis.

Ossiculum orbiculare Silvii.

Stapes.

Vestibulum.

Canalis semicircularis su-
perior.

Canalis semicircularis pos-
terior.

Canalis semicircularis in-
ferior.

Cochlea.

Cupola cochleae.

No. 336.

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